Fixing a code block in the PostgreSQL base dialect docstring.
Fixing a code block in the PostgreSQL base dialect docstring.

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