fix(Camera): test video definition in notifyReceivedVideoSize, can be null if...

fix(Camera): test video definition in notifyReceivedVideoSize, can be null if receiver disconnects at first frame received

src/components/camera/Camera.cpp

@@ -156,6 +156,11 @@ void CameraRenderer::updateWindowId () {
 
 bool CameraRenderer::notifyReceivedVideoSize () const {
   shared_ptr<const linphone::VideoDefinition> videoDefinition = mCall->getCurrentParams()->getReceivedVideoDefinition();
+
+  // Can be null if the receiver quickly disconnects. Rare but possible.
+  if (!videoDefinition)
+    return false;
+
   unsigned int width = videoDefinition->getWidth();
   unsigned int height = videoDefinition->getHeight();