correct example config for MCH ErrorTask (#1808)

Author: pillot

Modules/MUON/MCH/etc/qc-errors.json

@@ -24,7 +24,7 @@
                 "maxNumberCycles": "-1",
                 "dataSource": {
                     "type": "direct",
-                    "query": "errors:MCH/ERRORS/0"
+                    "query": "errors:MCH/PROCERRORS/0"
                 }
             }
         }