Drop unneeded condition in SourceMap class.
Drop unneeded condition in SourceMap class.

kaicataldo/babel,babel/babel,bcoe/babel,jridgewell/babel,maurobringolf/babel,claudiopro/babel,ccschneidr/babel,zjmiller/babel,shuhei/babel,vadzim/babel,KunGha/babel,guybedford/babel,existentialism/babel,iamchenxin/babel,vadzim/babel,hulkish/babel,lxe/babel,kellyselden/babel,STRML/babel,samwgoldman/babel,iamchenxin/babel,maurobringolf/babel,kedromelon/babel,tikotzky/babel,babel/babel,hzoo/babel,shuhei/babel,kellyselden/babel,jridgewell/babel,chicoxyzzy/babel,kaicataldo/babel,jchip/babel,hulkish/babel,PolymerLabs/babel,chicoxyzzy/babel,jchip/babel,chicoxyzzy/babel,hzoo/babel,PolymerLabs/babel,guybedford/babel,claudiopro/babel,hulkish/babel,Skillupco/babel,kellyselden/babel,STRML/babel,kellyselden/babel,hzoo/babel,jridgewell/babel,existentialism/babel,zjmiller/babel,kassens/babel,zertosh/babel,zertosh/babel,rmacklin/babel,shuhei/babel,PolymerLabs/babel,babel/babel,chicoxyzzy/babel,kassens/babel,KunGha/babel,babel/babel,kaicataldo/babel,tikotzky/babel,jridgewell/babel,claudiopro/babel,ccschneidr/babel,maurobringolf/babel,Skillupco/babel,kaicataldo/babel,lxe/babel,Skillupco/babel,hzoo/babel,Skillupco/babel,garyjN7/babel,hulkish/babel,kedromelon/babel,iamchenxin/babel,rmacklin/babel,bcoe/babel,samwgoldman/babel,samwgoldman/babel,existentialism/babel,garyjN7/babel,kedromelon/babel,guybedford/babel