#2058 PTVS crash when trying to do relative import in the REPL
#2058 PTVS crash when trying to do relative import in the REPL

Add missing null check before calling EndsWith on a string.

dut3062796s/PTVS,ChinaQuants/PTVS,int19h/PTVS,denfromufa/PTVS,gomiero/PTVS,alanch-ms/PTVS,juanyaw/PTVS,gilbertw/PTVS,modulexcite/PTVS,crwilcox/PTVS,DinoV/PTVS,juanyaw/PTVS,christer155/PTVS,msunardi/PTVS,christer155/PTVS,int19h/PTVS,xNUTs/PTVS,DinoV/PTVS,dut3062796s/PTVS,gilbertw/PTVS,alanch-ms/PTVS,int19h/PTVS,crwilcox/PTVS,fivejjs/PTVS,Microsoft/PTVS,Habatchii/PTVS,modulexcite/PTVS,xNUTs/PTVS,ChinaQuants/PTVS,bolabola/PTVS,huguesv/PTVS,christer155/PTVS,DEVSENSE/PTVS,zooba/PTVS,bolabola/PTVS,denfromufa/PTVS,fjxhkj/PTVS,MetSystem/PTVS,christer155/PTVS,ChinaQuants/PTVS,dut3062796s/PTVS,msunardi/PTVS,fivejjs/PTVS,fjxhkj/PTVS,christer155/PTVS,modulexcite/PTVS,gomiero/PTVS,crwilcox/PTVS,modulexcite/PTVS,alanch-ms/PTVS,Habatchii/PTVS,bolabola/PTVS,zooba/PTVS,DEVSENSE/PTVS,Habatchii/PTVS,ChinaQuants/PTVS,huguesv/PTVS,fjxhkj/PTVS,crwilcox/PTVS,alanch-ms/PTVS,denfromufa/PTVS,xNUTs/PTVS,denfromufa/PTVS,bolabola/PTVS,DEVSENSE/PTVS,juanyaw/PTVS,fivejjs/PTVS,DEVSENSE/PTVS,fjxhkj/PTVS,bolabola/PTVS,gomiero/PTVS,gilbertw/PTVS,msunardi/PTVS,Habatchii/PTVS,gomiero/PTVS,fjxhkj/PTVS,modulexcite/PTVS,gomiero/PTVS,jkorell/PTVS,juanyaw/PTVS,Habatchii/PTVS,int19h/PTVS,DinoV/PTVS,huguesv/PTVS,xNUTs/PTVS,Microsoft/PTVS,denfromufa/PTVS,Habatchii/PTVS,huguesv/PTVS,denfromufa/PTVS,mlorbetske/PTVS,gilbertw/PTVS,huguesv/PTVS,MetSystem/PTVS,crwilcox/PTVS,gilbertw/PTVS,ChinaQuants/PTVS,Microsoft/PTVS,Microsoft/PTVS,christer155/PTVS,DinoV/PTVS,mlorbetske/PTVS,ChinaQuants/PTVS,huguesv/PTVS,mlorbetske/PTVS,Microsoft/PTVS,MetSystem/PTVS,fivejjs/PTVS,modulexcite/PTVS,gilbertw/PTVS,DinoV/PTVS,DinoV/PTVS,jkorell/PTVS,xNUTs/PTVS,zooba/PTVS,DEVSENSE/PTVS,alanch-ms/PTVS,mlorbetske/PTVS,fivejjs/PTVS,gomiero/PTVS,MetSystem/PTVS,int19h/PTVS,zooba/PTVS,dut3062796s/PTVS,juanyaw/PTVS,mlorbetske/PTVS,xNUTs/PTVS,MetSystem/PTVS,Microsoft/PTVS,jkorell/PTVS,msunardi/PTVS,fjxhkj/PTVS,MetSystem/PTVS,dut3062796s/PTVS,msunardi/PTVS,dut3062796s/PTVS,alanch-ms/PTVS,int19h/PTVS,jkorell/PTVS,zooba/PTVS,msunardi/PTVS,zooba/PTVS,DEVSENSE/PTVS,bolabola/PTVS,fivejjs/PTVS,jkorell/PTVS,jkorell/PTVS,crwilcox/PTVS,mlorbetske/PTVS,juanyaw/PTVS