Make nova compute deployable on SLE12

This change makes Nova Compute deployable on SLES 12 and Chef 11
It is ok, as it is. In qemu.conf there is section with examples and additional space in regexp will uncomment all of them
```
# Some examples of valid values are:
#
#       user = "qemu"   # A user named "qemu"
#       user = "+0"     # Super user (uid=0)
#       user = "100"    # A user named "100" or a user with uid=100
#
#user = "root"
```