'open' flavour fails to build with fdroidserver

[licaon-kter]

Since 0ef3b91 it says:

BUG: buildserver > ==== detail begin ====
DEBUG: buildserver > Found 5.4.1 via distributionUrl
DEBUG: buildserver > Running /opt/gradle/versions/5.4.1/bin/gradle assembleOpenProdRelease
DEBUG: buildserver >
DEBUG: buildserver > > Configure project :xabber
DEBUG: buildserver > WARNING: Configuration 'compile' is obsolete and has been replaced with 'implementation' and 'api'.
DEBUG: buildserver > It will be removed soon. For more information see: http://d.android.com/r/tools/update-dependency-configurations.html
DEBUG: buildserver > WARNING: Configuration 'releaseCompile' is obsolete and has been replaced with 'releaseImplementation' and 'releaseApi'.
DEBUG: buildserver > It will be removed soon. For more information see: http://d.android.com/r/tools/update-dependency-configurations.html
DEBUG: buildserver > WARNING: Configuration 'debugCompile' is obsolete and has been replaced with 'debugImplementation' and 'debugApi'.
DEBUG: buildserver > It will be removed soon. For more information see: http://d.android.com/r/tools/update-dependency-configurations.html
DEBUG: buildserver > WARNING: API 'variant.getJavaCompile()' is obsolete and has been replaced with 'variant.getJavaCompileProvider()'.
DEBUG: buildserver > It will be removed at the end of 2019.
DEBUG: buildserver > For more information, see https://d.android.com/r/tools/task-configuration-avoidance.
DEBUG: buildserver > To determine what is calling variant.getJavaCompile(), use -Pandroid.debug.obsoleteApi=true on the command line to display more information.
DEBUG: buildserver >
DEBUG: buildserver > FAILURE: Build failed with an exception.
DEBUG: buildserver >
DEBUG: buildserver > * What went wrong:
DEBUG: buildserver > Could not determine the dependencies of task ':xabber:lintVitalOpenProdRelease'.
DEBUG: buildserver > > Could not resolve all artifacts for configuration ':xabber:storeProdDebugCompileClasspath'.
DEBUG: buildserver >    > Failed to transform artifact 'MemorizingTrustManager.aar (project :xabber:MemorizingTrustManager)' to match attributes {artifactType=jar}.
DEBUG: buildserver >       > Execution failed for JetifyTransform: /home/vagrant/build/com.xabber.android/xabber/MemorizingTrustManager/build/outputs/aar/MemorizingTrustManager-release.aar.
DEBUG: buildserver >          > Failed to transform '/home/vagrant/build/com.xabber.android/xabber/MemorizingTrustManager/build/outputs/aar/MemorizingTrustManager-release.aar' using Jetifier. Reason: Cannot open a library at 'FileMapping(from=/home/vagrant/build/com.xabber.android/xabber/MemorizingTrustManager/build/outputs/aar/MemorizingTrustManager-release.aar, to=/home/vagrant/build/com.xabber.android/xabber/MemorizingTrustManager/build/.transforms/a1730bfd42e1358111fae7a254ecf52e/jetified-MemorizingTrustManager-release.aar)'. (Run with --stacktrace for more details.)
DEBUG: buildserver >    > Failed to transform artifact 'emojicon.aar (project :xabber:emojicon)' to match attributes {artifactType=jar}.
DEBUG: buildserver >       > Execution failed for JetifyTransform: /home/vagrant/build/com.xabber.android/xabber/emojicon/build/outputs/aar/emojicon-release.aar.
DEBUG: buildserver >          > Failed to transform '/home/vagrant/build/com.xabber.android/xabber/emojicon/build/outputs/aar/emojicon-release.aar' using Jetifier. Reason: Cannot open a library at 'FileMapping(from=/home/vagrant/build/com.xabber.android/xabber/emojicon/build/outputs/aar/emojicon-release.aar, to=/home/vagrant/build/com.xabber.android/xabber/emojicon/build/.transforms/dd1d20b9cd69a8522270d0faa5c3e3d1/jetified-emojicon-release.aar)'. (Run with --stacktrace for more details.)
DEBUG: buildserver >
DEBUG: buildserver > * Try:
DEBUG: buildserver > Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.
DEBUG: buildserver >
DEBUG: buildserver > * Get more help at https://help.gradle.org
DEBUG: buildserver >
DEBUG: buildserver > Deprecated Gradle features were used in this build, making it incompatible with Gradle 6.0.
DEBUG: buildserver > Use '--warning-mode all' to show the individual deprecation warnings.
DEBUG: buildserver > See https://docs.gradle.org/5.4.1/userguide/command_line_interface.html#sec:command_line_warnings
DEBUG: buildserver >
DEBUG: buildserver > BUILD FAILED in 28s

...note that it includes #898 else it won't even try.