Prevent adding storage to a running jail
Steps to reproduce:
1) Create Jail.
2) Start Jail.
3) Edit MountPoint and add mountpoint.
4) Jail disappears off jails list.
@ CLI `iocage list` barfs errors. (thus why UI fails to return list)
UI should not allow you to add a mountpoint to running Jail.
Since iocage is now b0rked, I'm not able to do anything to remove jail to fix the system.