Elastix PBX - Voicemail Disabled After Yum Update

I ran a yum update process on my Elastix PBX, updating all the packages.  The update process completed without error; however, voicemail was disabled on all user extensions.  Here's how I fixed it. 

* SSH into the PBX and cd to /etc/asterisk.
* Find voicemail.conf.  If you cat it, you'll notice it's basically empty.  But don't have a heart attack just yet.
* You should also see a file called something like voicemail.conf.old_DATE_TIME (e.g. voicemail.conf.old_2015Feb12_183454).  The date should match the date you performed the fateful yum update command.  If you cat this file, you should see that it contains your proper voicemail user configuration.
* Backup voicemail.conf to be safe.
* Restore the data in the backup file to voicemail.conf.  You can copy/paste, cp, etc.
* Make sure the permissions, owner, and group match.  They should be 664 with owner and group set to "asterisk."  You'll see these same settings on the other voicemail configuration files.
* Apply the configuration.  I usually just click somewhere in the Elastix web GUI to get the "Apply Config" link to appear and click it.
* Look at a few extensions in the web GUI, and you should see that voicemail is now enabled.  Disaster averted!