update comment on ignoring repositories.config

VisualStudio.gitignore

@@ -137,7 +137,7 @@ publish/
 **/packages/*
 # except build/, which is used as an MSBuild target.
 !**/packages/build/
-# If using the old MSBuild-Integrated Package Restore, uncomment this:
+# Uncomment if necessary however generally it will be regenerated when needed
 #!**/packages/repositories.config
 
 # Windows Azure Build Output