vngspice.vcxproj, unify, <PrecompiledHeader> and <CompileAsManaged>

visualc/vngspice.vcxproj

@@ -229,7 +229,6 @@
       <DebugInformationFormat>EditAndContinue</DebugInformationFormat>
       <CompileAs>CompileAsC</CompileAs>
       <MultiProcessorCompilation>true</MultiProcessorCompilation>
-      <CompileAsManaged>false</CompileAsManaged>
     </ClCompile>
     <Link>
       <AdditionalDependencies>psapi.lib;%(AdditionalDependencies)</AdditionalDependencies>
@@ -641,7 +640,8 @@
       <RuntimeLibrary>MultiThreaded</RuntimeLibrary>
       <RuntimeTypeInfo>true</RuntimeTypeInfo>
       <OpenMPSupport>true</OpenMPSupport>
-      <PrecompiledHeader>NotUsing</PrecompiledHeader>
+      <PrecompiledHeader>
+      </PrecompiledHeader>
       <WarningLevel>Level3</WarningLevel>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
       <CompileAs>CompileAsC</CompileAs>