Fix output of `econe-describe-addresses
Fix output of `econe-describe-addresses

The current with of the IP address column is too small: The IP address "192.168.1.64", for instance, is 12 characters long, and gets truncated to "192.168.1.". Reserving 15 should do:

    irb(main):001:0> "XXX.XXX.XXX.XXX".length
    => 15
    irb(main):002:0>
atodorov-storpool/one,alvarosimon/one,abelCoronado93/one,atodorov-storpool/one,atodorov-storpool/one,baby-gnu/one,alvarosimon/one,goberle/one,atodorov-storpool/one,goberle/one,unistra/one,goberle/one,abelCoronado93/one,atodorov-storpool/one,hsanjuan/one,atodorov-storpool/one,baby-gnu/one,atodorov-storpool/one,OpenNebula/one,juanmont/one,OpenNebula/one,alvarosimon/one,ohamada/one,goberle/one,unistra/one,unistra/one,ohamada/one,juanmont/one,alvarosimon/one,hsanjuan/one,abelCoronado93/one,hsanjuan/one,abelCoronado93/one,abelCoronado93/one,juanmont/one,juanmont/one,baby-gnu/one,OpenNebula/one,baby-gnu/one,ohamada/one,unistra/one,ohamada/one,abelCoronado93/one,ohamada/one,goberle/one,baby-gnu/one,unistra/one,unistra/one,juanmont/one,unistra/one,juanmont/one,goberle/one,juanmont/one,OpenNebula/one,hsanjuan/one,juanmont/one,OpenNebula/one,OpenNebula/one,ohamada/one,atodorov-storpool/one,ohamada/one,unistra/one,baby-gnu/one,atodorov-storpool/one,juanmont/one,OpenNebula/one,hsanjuan/one,alvarosimon/one,OpenNebula/one,hsanjuan/one,alvarosimon/one,abelCoronado93/one,abelCoronado93/one,baby-gnu/one,alvarosimon/one,goberle/one,alvarosimon/one,baby-gnu/one,hsanjuan/one,hsanjuan/one,OpenNebula/one,ohamada/one,goberle/one