Fix for "fatal: Not a valid object name" when displaying a nonexistent file blob

When browsing through file history: a click on a commit containing deletion of the file caused the error.
Merge pull request #2501 from qgppl/gp/fix-FileViewer

Fix for "fatal: Not a valid object name" when displaying a nonexistent blob
.nuget directory case fixed
Settings stored at the Distributed level always have to be set directly
Merge branch 'release/2.48'