remove obsolete prop

Author: T-Gro

tests/FSharp.Test.Utilities/FSharp.Test.Utilities.fsproj

@@ -5,7 +5,6 @@
     <TargetFrameworks Condition="'$(OS)' == 'Unix' or '$(BUILDING_USING_DOTNET)' == 'true'">$(FSharpNetCoreProductTargetFramework)</TargetFrameworks>
     <RuntimeIdentifiers>win-x86;win-x64;linux-x64;osx-x64</RuntimeIdentifiers>
     <AssetTargetFallback>$(AssetTargetFallback);portable-net45+win8+wp8+wpa81</AssetTargetFallback>
-    <ReferenceVsAssemblies>true</ReferenceVsAssemblies>
     <OutputType>Library</OutputType>
     <DisableImplicitFSharpCoreReference>true</DisableImplicitFSharpCoreReference>
     <UnitTestType>xunit</UnitTestType>

tests/fsharp/FSharpSuite.Tests.fsproj

@@ -6,7 +6,6 @@
     <TargetFrameworks Condition="'$(OS)' == 'Unix' or '$(BUILDING_USING_DOTNET)' == 'true'">$(FSharpNetCoreProductTargetFramework)</TargetFrameworks>
     <RuntimeIdentifiers>win-x86;win-x64</RuntimeIdentifiers>
     <AssetTargetFallback>$(AssetTargetFallback);portable-net45+win8+wp8+wpa81</AssetTargetFallback>
-    <ReferenceVsAssemblies>true</ReferenceVsAssemblies>
     <OutputType>Library</OutputType>
     <DisableImplicitFSharpCoreReference>true</DisableImplicitFSharpCoreReference>
     <Optimize>false</Optimize>