Add back TargetFrameworkMoniker to fix build machine in vs15

Author: mjbvz

Build/Common.Build.settings

@@ -31,6 +31,7 @@
     <BuildingInsideVisualStudio Condition="'$(BuildingInsideVisualStudio)' == ''">false</BuildingInsideVisualStudio>
 
     <TargetFrameworkVersion Condition="'$(TargetFrameworkVersion)' == ''">v4.6</TargetFrameworkVersion>
+    <TargetFrameworkMoniker>.NETFramework,Version=$(TargetFrameworkVersion)</TargetFrameworkMoniker>
 
     <VSToolsPath Condition="'$(VSToolsPath)' == ''">$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)</VSToolsPath>