Reload service rather than restart

[amendlik]

The Salt Minion does not react well to FirewallD being restarted. It becomes unreachable indefinitely, until it is restarted. Further, I don't know of any reasons to restart the FirewallD service, since the service dynamically manages the kernel module.

This PR makes the service reload its conifg, rather than restarting.

[aboe76]

looks good to me,
tested it without issues.

[javierbertoli]

@amendlik Mind you either modify the comments (to reflect the new behaviour) or remove them, for consistency?

[amendlik]

After some more testing, reloading the service (systemctl reload firewalld) is exhibiting some strange behaviors, sometimes causing firewalld to stop. Using the firewall-cmd --reload command seems to work predictably every time.

[aboe76]

why not keep the listen_in?

that way only after all the changes it will be reloaded, instead of everytime.

[amendlik]

listen_in will move the reload command to the very end of the entire state run, including states from outside of this formula. The way I wrote it, the reload will happen once, at the end of everything in this formula.
My thinking is that, if later states require the firewall to be configured, we would want to complete that before moving on to other formulas, etc. I'm happy to hear other ideas on how this should work.

[aboe76]

@amendlik then I see no problems, @javierbertoli shall we merge this?

[javierbertoli]

@amendlik 's arguments are reasonable, so I'll merge. Thanks you guys!