only warn once per window when no video options are found

xpra/server/window/video_compress.py

@@ -1848,7 +1848,7 @@ def setup_pipeline(self, scores : tuple, width: int, height: int, src_format : s
             self.csc_clean(self._csc_encoder)
             self.ve_clean(self._video_encoder)
         end = monotonic()
-        if not self.is_cancelled():
+        if not self.is_cancelled() and first_time(f"novideo-{src_format}-{self.wid}"):
             videolog("setup_pipeline(..) failed! took %.2fms", (end-start)*1000.0)
             videolog.error("Error: failed to setup a video pipeline for %s at %ix%i", src_format, width, height)
             videolog.error(" tried the following options")