fix error, refs #20596

tests/test_mediaworker.py

@@ -53,7 +53,7 @@ def check_celerity_connectivity(ip):
     print('Checking celerity connectivity: %s' % cmd)
     try:
         d = subprocess.check_output(cmd, shell=True, timeout=5)
-    except exception:
+    except subprocess.CalledProcessError:
         d = ''
     if "Celerity tasks server" in d:
         print('%sSuccessfully reached tasks server%s' % (GREEN, DEF))