Dropped code which disabled manual network configuration. bnc#858523

The resolution on disabling the manual network configuration is done in
the client (yast2-network/inst_lan.rb) itself. yast2-network currently
implements in automatic net configuration. If automatic configuration
fails then the dialog is shown.
Updated changelog
Merge pull request #169 from mchf/bnc858523-manual-net-config

Enable manual net config