DeckLink cap.: fixed capturing of PsF

When PsF was captured, there is not a right mode and thus the callback
is repeatedly called if the change is not skipped.

Reference: BMD ticket DEV-3656

src/video_capture/decklink.cpp

@@ -251,6 +251,9 @@ public:
                         reason = "unknown";
                 }
                 LOG(LOG_LEVEL_NOTICE) << MODULE_NAME << "Format change detected (" << reason << ").\n";
+                if ((notificationEvents & (bmdVideoInputDisplayModeChanged | bmdVideoInputColorspaceChanged)) == 0U) {
+                        return S_OK;
+                }
 
                 unique_lock<mutex> lk(s->lock);
 		if ((flags & bmdDetectedVideoInputDualStream3D) != 0u && !s->stereo) {