build: fix syntax errors in the Visual Studio projects.

neercs/neercs.vcxproj

@@ -78,6 +78,8 @@
   <ItemGroup>
     <ProjectReference Include="$(SolutionDir)\..\..\src\lolcore.vcxproj">
       <Project>{9e62f2fe-3408-4eae-8238-fd84238ceeda}</Project>
+    </ProjectReference>
+    <ProjectReference Include="$(SolutionDir)\..\..\src\lolbullet.vcxproj">
       <Project>{83d3b207-c601-4025-8f41-01dedc354661}</Project>
     </ProjectReference>
   </ItemGroup>