handle missing pillow more gracefully

xpra/codecs/icon_util.py

@@ -54,16 +54,16 @@ def load_icon_from_file(filename: str, max_size: int = MAX_ICON_SIZE) -> tuple:
         return ()
     log("load_icon_from_file(%s, %i)", filename, max_size)
     if filename.endswith("xpm"):
-        from PIL import Image  # pylint: disable=import-outside-toplevel
         img = None
         try:
+            from PIL import Image  # pylint: disable=import-outside-toplevel
             img = Image.open(filename)
             buf = BytesIO()
             img.save(buf, "PNG")
             pngicondata = buf.getvalue()
             buf.close()
             return pngicondata, "png"
-        except ValueError as e:
+        except (ValueError, ImportError) as e:
             log(f"Image.open({filename}) {e}", exc_info=True)
         except Exception as e:
             log(f"Image.open({filename})", exc_info=True)