Comment 1 for bug 1458480

Example of the exception in case of aa-enforce:

Traceback:
 Traceback (most recent call last):
   File "/usr/sbin/aa-enforce", line 30, in <module>
     tool.cmd_enforce()
   File "/usr/lib/python3/dist-packages/apparmor/tools.py", line 166, in cmd_enforce
     raise apparmor.AppArmorException(cmd_info[1])
 apparmor.common.AppArmorException: 'Warning: unable to find a suitable fs in /proc/mounts, is it mounted?\nUse --subdomainfs to override.\n'