UI: Fix "unreferenced local function" warning

Fixes the following warning:

warning C4505: 'operator ==' : unreferenced local function has been
removed

This function actually is used despite this warning, so the only way to
get rid of the warning is to disable the warning itself in this
particular case.

obs/properties-view.moc.hpp

@@ -10,6 +10,10 @@
 
 #include <vector>
 
+#ifdef _MSC_VER
+#pragma warning(disable : 4505)
+#endif
+
 static bool operator!=(const media_frames_per_second &a,
 		const media_frames_per_second &b)
 {