Pipeline parsing and setting correct timestamp

This is my Log message

message

2017-05-22T03:10:16+00:00 itc2000 daemon info itcTransceiver[1320]: Timer: Transmission start - 23710608us - 0x1169cb90 (now: 23578441us)

This is test extractor from message

test

2017-05-22T03:10:16+00:00

and this is timestamp that I want to replace

timestamp

2017-06-27T12:08:01.000Z

This is regular expression that I use to extract timestamp from message to test

^([0-9]{4}-[0-9]{2}-[0-9]{2}T[0-9]{2}:[0-9]{2}:[0-9]{2}[+-][0-9]{2}:[0-9]{2}).*$

Do you see some error?

Error on graylog log

facility
runit-service

gl2_processing_error
For rule ‘parse event timestamp’: In call to function ‘parse_date’ at 5:26 an exception was thrown: Invalid format: “”

level
6

message
at com.lmax.disruptor.WorkProcessor.run(WorkProcessor.java:143) [graylog.jar:?]

source
graylog-server

timestamp
2017-07-03T08:00:21.392Z