Fix sources.proj reference to SafeInt3.hpp.

Wrong path was used, causing VS to always touch the project.

Author: vslavik

Release/src/build/sources.proj

@@ -82,7 +82,7 @@
     <ClInclude Include="$(CasablancaIncludeDir)\cpprest\rawptrstream.h">
       <Filter>Header Files\cpprest</Filter>
     </ClInclude>
-    <ClInclude Include="$(CasablancaIncludeDir)\cpprest\compat\SafeInt3.hpp">
+    <ClInclude Include="$(CasablancaIncludeDir)\compat\SafeInt3.hpp">
       <Filter>Header Files\cpprest</Filter>
     </ClInclude>
     <ClInclude Include="$(CasablancaIncludeDir)\cpprest\streams.h">