Don't specify a specific SDK when building for UWP

Instead use the latest version installed

VisualC-WinRT/SDL-UWP.vcxproj

@@ -419,8 +419,7 @@
     <ApplicationTypeRevision>8.2</ApplicationTypeRevision>
     <TargetPlatformVersion>10.0.16299.0</TargetPlatformVersion>
     <TargetPlatformMinVersion>10.0.16299.0</TargetPlatformMinVersion>
-    <WindowsTargetPlatformVersion>10.0.16299.0</WindowsTargetPlatformVersion>
-    <WindowsTargetPlatformMinVersion>10.0.16299.0</WindowsTargetPlatformMinVersion>
+    <WindowsTargetPlatformVersion>10.0</WindowsTargetPlatformVersion>
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="Configuration">
@@ -598,4 +597,4 @@
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">
   </ImportGroup>
-</Project>
+</Project>