SIGSEGV issue -[MQTTSession closeInternal]

[yuchern]

Crash when app enter foreground
0s crash
0s applicationWillEnterForeground:()UIApplication
862s applicationDidEnterBackground:()UIApplication

SIGSEGV crash
#1 com.tcl.tclplus.home.MQTTSSLSecurityPolicyTransport.queue

libobjc.A.dylib 0x197400450 objc_release
CoreFoundation 0x180377c10
TCLPlus 0x100c64214 -[MQTTSession closeInternal] (MQTTSession.m:577)
TCLPlus 0x100c6878c -[MQTTSession error:error:] (MQTTSession.m:1262)
TCLPlus 0x100c684dc -[MQTTSession connectionError:] (MQTTSession.m:1238)
TCLPlus 0x100c56f6c -[MQTTCFSocketTransport encoder:didFailWithError:] (MQTTCFSocketTransport.m:0)
TCLPlus 0x100c5602c -[MQTTCFSocketEncoder stream:handleEvent:] (MQTTCFSocketEncoder.m:77)
TCLPlus 0x100c6fe2c -[MQTTSSLSecurityPolicyEncoder stream:handleEvent:] (MQTTSSLSecurityPolicyEncoder.m:0)
CoreFoundation 0x18044b30c
CoreFoundation 0x180465e34
libdispatch.dylib 0x1800b12ec
libdispatch.dylib 0x1800b22f0
libdispatch.dylib 0x18008d410
libdispatch.dylib 0x18008deb8
libdispatch.dylib 0x18009776c
libsystem_pthread.dylib 0x1d9982f38 _pthread_wqthread