As the shepherd adds these to the logs.
* gnu/services/guix.scm (make-guix-build-coordinator-start-script): Pass
#:timestamp-log-output? #f to make-build-coordinator.
(guix-build-coordinator-agent-shepherd-services): Add
--timestamp-log-output=false to the arguments.
Change-Id: I9073ee7b1cefa894d38fdf3831c59de693e087f6