airodump-ng: don't increment columns_ap twice.

 * r2271 added the feature to show an uptime column.
   When this feature is enabled columns_ap is incremented
   despite of the option manufacturer beeing enabled or not.
   So it shouldn't be increment twice when manufacturer is
   enabled.

 * Terminal resizing was broken before this change when
   the option manufacturer is enabled.



git-svn-id: http://trac.aircrack-ng.org/svn/trunk@2275 28c6078b-6c39-48e3-add9-af49d547ecab