Remove remnants of native file dialogs

src/common/common.vcxproj

@@ -39,7 +39,6 @@
     <ClInclude Include="text.h" />
     <ClInclude Include="textenums.h" />
     <ClInclude Include="textevents.h" />
-    <ClInclude Include="thread.h" />
     <ClInclude Include="tree.h" />
     <ClInclude Include="typedef.h" />
     <ClInclude Include="url.h" />
@@ -70,7 +69,6 @@
     <ClCompile Include="servlist.c" />
     <ClCompile Include="ssl.c" />
     <ClCompile Include="text.c" />
-    <ClCompile Include="thread.c" />
     <ClCompile Include="tree.c" />
     <ClCompile Include="url.c" />
     <ClCompile Include="userlist.c" />