Don't show warnings while building .NET Core 1.1

Author: Konstantin Sharon

Directory.Build.props

@@ -2,7 +2,5 @@
 	<PropertyGroup>
 		<!-- Compile Include="x.cs" doesn't use LangVersion defined in the PropertyGroup -->
 		<LangVersion>9.0</LangVersion>
-
-		<NoWarn Condition=" '(TargetFramework)' != 'netcoreapp1.0' and '(TargetFramework)' != 'netcoreapp1.1' ">$(NoWarn);NETSDK1138</NoWarn>
 	</PropertyGroup>
 </Project>