util.py: ignore decoding errors

greentest/util.py

@@ -188,7 +188,7 @@ def run(command, **kwargs):
     assert not err
     with lock:
         if out:
-            out = out.strip().decode()
+            out = out.strip().decode('utf-8', 'ignore')
             if out:
                 out = '  ' + out.replace('\n', '\n  ')
                 out = out.rstrip()