fix docstring typo
fix docstring typo

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