fix typo in vcxproj template

templates/vsprojects/vcxproj_defs.include

@@ -56,7 +56,7 @@ ${gen_package_props(packages)}\
     <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
     <Import Project="..\global.props" />
     % for prop in additional_props:
-    <Import Project="..\${prop}." />
+    <Import Project="..\${prop}.props" />
     % endfor
   </ImportGroup>
   <PropertyGroup Label="UserMacros" />

vsprojects/grpc_csharp_ext/grpc_csharp_ext.vcxproj

@@ -46,7 +46,7 @@
   <ImportGroup Label="PropertySheets" Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
     <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
     <Import Project="..\global.props" />
-    <Import Project="..\winsock." />
+    <Import Project="..\winsock.props" />
   </ImportGroup>
   <PropertyGroup Label="UserMacros" />
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">