never expose pillow enums in network packets

xpra/codecs/pillow/encoder.py

@@ -182,7 +182,7 @@ def encode(coding : str, image, options=None) -> Tuple[str,Compressed,Dict[str,A
         else:
             resample = LANCZOS
         im = im.resize((scaled_width, scaled_height), resample=resample)
-        client_options["resample"] = resample
+        client_options["resample"] = getattr(resample, "name", str(resample))
     if coding in ("jpeg", "webp"):
         #newer versions of pillow require explicit conversion to non-alpha:
         if pixel_format.find("A")>=0 and coding=="jpeg":