try harder to avoid slow modules (ie: csc_cython)

xpra/server/window/video_scoring.py

@@ -102,7 +102,7 @@ def get_pipeline_score(enc_in_format, csc_spec, encoder_spec,
     def clamp(v):
         return max(0, min(100, v))
     qscore = clamp(get_quality_score(enc_in_format, csc_spec, encoder_spec, scaling, target_quality, min_quality))
-    sscore = clamp(get_speed_score(enc_in_format, csc_spec, encoder_spec, scaling, target_speed, min_speed))
+    sscore = get_speed_score(enc_in_format, csc_spec, encoder_spec, scaling, target_speed, min_speed)
 
     #multiplier for setup_cost:
     #(lose points if we have less than N fps)