add 'gosu' to be installed, needed for better fix of webrecorder/brow…

…sertrix-crawler#502 (#18)

Dockerfile

@@ -11,7 +11,7 @@ RUN echo "ttf-mscorefonts-installer msttcorefonts/accepted-mscorefonts-eula sele
 RUN apt-get update -y && apt-get install --no-install-recommends -qqy software-properties-common \
     && apt-get update -y \
     && DEBIAN_FRONTEND=noninteractive apt-get install --no-install-recommends -qqy build-essential locales-all redis-server apt-transport-https  \
-      curl git socat jq xvfb x11vnc gpg gpg-agent ca-certificates libnss3 libatk1.0-0 libatk-bridge2.0-0 libcups2 \
+      curl git socat jq xvfb x11vnc gosu gpg gpg-agent ca-certificates libnss3 libatk1.0-0 libatk-bridge2.0-0 libcups2 \
       libxkbcommon0 libxcomposite1 libxdamage1 libxrandr2 libgbm1 libpango-1.0-0 libcairo2 libasound2 libgtk-3-0 \
       libxtst6 xdg-utils libc-bin hicolor-icon-theme python3-pip python3-dev \
       fonts-arphic-ukai fonts-arphic-uming fonts-freefont-ttf fonts-gfs-neohellenic fonts-indic fonts-ipafont-mincho fonts-ipafont-gothic fonts-kacst \