Add another exception case to Firebird' is_disconnect()
Add another exception case to Firebird' is_disconnect()

davidfraser/sqlalchemy,sandan/sqlalchemy,276361270/sqlalchemy,itkovian/sqlalchemy,monetate/sqlalchemy,EvaSDK/sqlalchemy,WinterNis/sqlalchemy,robin900/sqlalchemy,j5int/sqlalchemy,Cito/sqlalchemy,elelianghh/sqlalchemy,graingert/sqlalchemy,brianv0/sqlalchemy,bootandy/sqlalchemy,davidfraser/sqlalchemy,bdupharm/sqlalchemy,davidjb/sqlalchemy,davidjb/sqlalchemy,zzzeek/sqlalchemy,ThiefMaster/sqlalchemy,Cito/sqlalchemy,dstufft/sqlalchemy,pdufour/sqlalchemy,itkovian/sqlalchemy,halfcrazy/sqlalchemy,graingert/sqlalchemy,monetate/sqlalchemy,epa/sqlalchemy,sandan/sqlalchemy,dstufft/sqlalchemy,inspirehep/sqlalchemy,wfxiang08/sqlalchemy,wujuguang/sqlalchemy,olemis/sqlalchemy,inspirehep/sqlalchemy,hsum/sqlalchemy,alex/sqlalchemy,halfcrazy/sqlalchemy,WinterNis/sqlalchemy,wfxiang08/sqlalchemy,j5int/sqlalchemy,alex/sqlalchemy,elelianghh/sqlalchemy,alex/sqlalchemy,Cito/sqlalchemy,wujuguang/sqlalchemy,brianv0/sqlalchemy,EvaSDK/sqlalchemy,ThiefMaster/sqlalchemy,robin900/sqlalchemy,bdupharm/sqlalchemy,276361270/sqlalchemy,epa/sqlalchemy,Akrog/sqlalchemy,Akrog/sqlalchemy,sqlalchemy/sqlalchemy,pdufour/sqlalchemy,olemis/sqlalchemy,hsum/sqlalchemy,bootandy/sqlalchemy