terse_json: Ignore taskName log record attribute

Signed-off-by: Kai A. Hiller <V02460@gmail.com>

Author: V02460

synapse/logging/_terse_json.py

@@ -44,6 +44,7 @@
     "processName",
     "relativeCreated",
     "stack_info",
+    "taskName",
     "thread",
     "threadName",
 }