Commented Unassigned: Update NuGet to 2.7 will keep the old nuget official feed source [3500]

Repro steps:
1. on a existing machine with older version of nuget installed
2. double click to install latest nuget 2.7 VSIX as in a upgrade fashion
3. check the package source


Expected: The nuget official feed source is replaced by nuget.org feed

Actual: Still there. nuget.org was added as another feed.
Comments: more info on this: To repro this bug, need to have multiple feeds including nuget official feed, where only nuget official feed is selected/checked. Also on PMC nuget official feed is selected as the active feed. The resulting nuget.config will be: <?xml version="1.0" encoding="utf-8"?> <configuration> <packageRestore> <add key="enabled" value="True" /> </packageRestore> <packageSources> <add key="NuGet Official Package Source" value="https://nuget.org/api/v2/" /> <add key="remote" value="c:\Packages" /> <add key="webmatrix" value="http://nuget.org/api/v2/curated-feeds/webmatrix/" /> </packageSources> <disabledPackageSources> <add key="remote" value="true" /> <add key="webmatrix" value="true" /> </disabledPackageSources> <activePackageSource> <add key="NuGet Official Package Source" value="https://nuget.org/api/v2/" /> </activePackageSource> </configuration>