Fix xrManagedApi target framework version.

Author: nitrocaster

src/editors/xrManagedApi/xrManagedApi.vcxproj

@@ -12,7 +12,7 @@
   </ItemGroup>
   <PropertyGroup Label="Globals">
     <ProjectGuid>{55B0E2CA-E27A-47FC-BC92-21ABDC1044F5}</ProjectGuid>
-    <TargetFrameworkVersion>v4.5.2</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.0</TargetFrameworkVersion>
     <Keyword>ManagedCProj</Keyword>
     <RootNamespace>xrManagedApi</RootNamespace>
   </PropertyGroup>