[rqd] [cuebot] Changing rqd.conf tags has no effect at the cuebot server

**Describe the bug**
If a host defines some tags in its `rqd.conf` file like `RQD_TAGS=util`, then runs rqd, which creates a host entry in cuebot, further editing the tags in `rqd.conf` and restarting the service has no effect on the cuebot server.

**To Reproduce**
Start with a `rqd.conf` containing a single tag, such as `RQD_TAGS=util`. Then startup rqd, and stop it after a few seconds. Then edit the `rqd.conf` to have some changed tags, such as `RQD_TAGS=util,test`. When rqd starts back up, cuebot only matches it by hostname, and doesn't update the new tags.

Only once the host is removed from cuebot, then rqd is restarted will the new tags appear on that host.

**Expected behavior**
Everytime rqd starts up, it should send its tags to cuebot, and cuebot should create the host or update an existing host with these new tags.

**Version Number**
HEAD