Fix jinja formatting issue

[richm]

Fix for the following warning:

TASK [linux-system-roles.timesync : Disable timemaster] ************************
[WARNING]: conditional statements should not include jinja2 templating
delimiters such as {{ }} or {% %}. Found: '{{ __timemstr }}' in
timesync_services

when, that, and similar are already interpreted as Jinja expressions and do not require the use of {{ }}

[richm]

[citest]