Do not allow deleting official package source. Work items: 1143
Do not allow deleting official package source. Work items: 1143

--HG--
extra : rebase_source : 79d9d7a18528d7e633e50a7dad8a773a56eb8ccb

jholovacs/NuGet,oliver-feng/nuget,xoofx/NuGet,antiufo/NuGet2,rikoe/nuget,antiufo/NuGet2,GearedToWar/NuGet2,alluran/node.net,zskullz/nuget,zskullz/nuget,jholovacs/NuGet,pratikkagda/nuget,oliver-feng/nuget,OneGet/nuget,chester89/nugetApi,RichiCoder1/nuget-chocolatey,chocolatey/nuget-chocolatey,mrward/NuGet.V2,indsoft/NuGet2,jholovacs/NuGet,zskullz/nuget,antiufo/NuGet2,akrisiun/NuGet,xero-github/Nuget,antiufo/NuGet2,mrward/nuget,alluran/node.net,mono/nuget,ctaggart/nuget,themotleyfool/NuGet,RichiCoder1/nuget-chocolatey,xoofx/NuGet,ctaggart/nuget,indsoft/NuGet2,mrward/NuGet.V2,OneGet/nuget,mrward/NuGet.V2,OneGet/nuget,indsoft/NuGet2,alluran/node.net,chocolatey/nuget-chocolatey,ctaggart/nuget,OneGet/nuget,xoofx/NuGet,oliver-feng/nuget,jholovacs/NuGet,mrward/NuGet.V2,mrward/NuGet.V2,xoofx/NuGet,jmezach/NuGet2,anurse/NuGet,indsoft/NuGet2,ctaggart/nuget,GearedToWar/NuGet2,alluran/node.net,GearedToWar/NuGet2,dolkensp/node.net,jmezach/NuGet2,mono/nuget,rikoe/nuget,mrward/NuGet.V2,jmezach/NuGet2,mono/nuget,mrward/nuget,dolkensp/node.net,jmezach/NuGet2,xoofx/NuGet,mrward/nuget,jmezach/NuGet2,akrisiun/NuGet,kumavis/NuGet,indsoft/NuGet2,kumavis/NuGet,pratikkagda/nuget,chester89/nugetApi,dolkensp/node.net,pratikkagda/nuget,mono/nuget,chocolatey/nuget-chocolatey,oliver-feng/nuget,atheken/nuget,RichiCoder1/nuget-chocolatey,rikoe/nuget,themotleyfool/NuGet,mrward/nuget,indsoft/NuGet2,pratikkagda/nuget,chocolatey/nuget-chocolatey,oliver-feng/nuget,jmezach/NuGet2,chocolatey/nuget-chocolatey,RichiCoder1/nuget-chocolatey,rikoe/nuget,GearedToWar/NuGet2,RichiCoder1/nuget-chocolatey,jholovacs/NuGet,RichiCoder1/nuget-chocolatey,antiufo/NuGet2,dolkensp/node.net,GearedToWar/NuGet2,GearedToWar/NuGet2,pratikkagda/nuget,pratikkagda/nuget,zskullz/nuget,mrward/nuget,atheken/nuget,themotleyfool/NuGet,chocolatey/nuget-chocolatey,antiufo/NuGet2,jholovacs/NuGet,mrward/nuget,anurse/NuGet,oliver-feng/nuget,xoofx/NuGet