sftp Client Windows Version

The project file for the wolfSFTP example client is specifying a
too-specific Windows target platform version. It is the only project
file specifying the version to four places. Removed it and using the
default Windows version for the version of the build tools.

Author: ejohnstown

ide/winvs/wolfsftp-client/wolfsftp-client.vcxproj

@@ -79,7 +79,6 @@
     <ProjectGuid>{8DD810D6-159B-4C40-B682-FCA11F9B3680}</ProjectGuid>
     <Keyword>Win32Proj</Keyword>
     <RootNamespace>wolfsftp-client</RootNamespace>
-    <WindowsTargetPlatformVersion>10.0.17134.0</WindowsTargetPlatformVersion>
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="Configuration">