Revert "Enable "Whole Program Optimization"."

This seems to break nested run on top of KVM. See
#14

This reverts commit defbb8dbb2797ef76177ea5a188249225a0e8021.

Author: Taogle2018

gvm/gvm.vcxproj

@@ -54,7 +54,6 @@
     <SpectreMitigation>false</SpectreMitigation>
     <DriverTargetPlatform>Desktop</DriverTargetPlatform>
     <_NT_TARGET_VERSION>0x0601</_NT_TARGET_VERSION>
-    <WholeProgramOptimization>true</WholeProgramOptimization>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'" Label="Configuration">
     <TargetVersion>Windows7</TargetVersion>
@@ -65,7 +64,6 @@
     <SpectreMitigation>false</SpectreMitigation>
     <DriverTargetPlatform>Desktop</DriverTargetPlatform>
     <_NT_TARGET_VERSION>0x0601</_NT_TARGET_VERSION>
-    <WholeProgramOptimization>true</WholeProgramOptimization>
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <ImportGroup Label="PropertySheets">