Monasca log transformer currently throws exceptions on encountering a
non-UTC time offset (+0000):
"""
"exception": "Invalid format: \"2019-08-08 17:39:45 +0100\" is malformed at \" +0100\"",
"config_parsers":"yyyy-MM-dd HH:mm:ss +0000,ISO8601"}
"""
This fix allows logstash to interpret any valid ISO8601 offset.
Change-Id: Id70c3dd9cdcf681e955931f18a054e19cc284c0a
Closes-Bug: #1839597
(cherry picked from commit 3010d4c3911db175facec519ffce51a7c0498003)