Fix compiling Windows installer on VC14.2

Author: kuba2k2

Tools/msi/bundle/bootstrap/pythonba.vcxproj

@@ -27,6 +27,7 @@
     <PlatformToolset Condition="'$(PlatformToolset)' == ''">v140</PlatformToolset>
     <ProjectGuid>{7A09B132-B3EE-499B-A700-A4B2157FEA3D}</ProjectGuid>
     <TargetName>PythonBA</TargetName>
+    <WindowsTargetPlatformVersion>10.0</WindowsTargetPlatformVersion>
   </PropertyGroup>
   <Import Project="..\..\wix.props" />
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />