lxc: Converting 'if, else' logic into a 'switch, case'

lxc: Converting 'if, else' logic into a 'switch, case'

The structure used to handle network entries was based on 'if,else'
conditions. This commit converts this ugly structure into a switch to
clearify each option of the handler.

Signed-off-by: Julio Faracco <jcfaracco@gmail.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>