Remove additional addresses from the correct ifcfg (bnc#749800).

NetworkDevices::Name is a lower layer than Lan::{type,device} and holds
data from the last updated ifcfg, not the one being currently
edited.
changes + version
Merge pull request #29 from mvidner/SLE-10-SP4

Remove additional addresses from the correct ifcfg (bnc#749800).