Fix for oops when removing ip_prefix from list
Fix for oops when removing ip_prefix from list

ralisi/olsrd_cl_roam,diogomg/olsrd-binary-heap,acinonyx/olsrd,sebkur/olsrd,tdz/olsrd,acinonyx/olsrd,ninuxorg/olsrd,diogomg/olsrd,ninuxorg/olsrd,nolith/olsrd,zioproto/olsrd,ralisi/olsrd_cl_roam,duydb2/olsr,duydb2/olsr,acinonyx/olsrd,duydb2/olsr,servalproject/olsr,nolith/olsrd,brabander/olsr,sebkur/olsrd,cholin/olsrd,cholin/olsrd,servalproject/olsr,diogomg/olsrd,duydb2/olsr,zioproto/olsrd,diogomg/olsrd-binary-heap,tdz/olsrd,tdz/olsrd,servalproject/olsr,diogomg/olsrd-binary-heap,cholin/olsrd,zioproto/olsrd,nolith/olsrd,duydb2/olsr,duydb2/olsr,ninuxorg/olsrd,diogomg/olsrd,brabander/olsr,tdz/olsrd,servalproject/olsr,diogomg/olsrd-binary-heap,tdz/olsrd,sebkur/olsrd,ninuxorg/olsrd,nolith/olsrd,diogomg/olsrd-binary-heap,ralisi/olsrd_cl_roam,diogomg/olsrd-binary-heap,zioproto/olsrd,servalproject/olsr,cholin/olsrd,acinonyx/olsrd,sebkur/olsrd,diogomg/olsrd,diogomg/olsrd,ninuxorg/olsrd,zioproto/olsrd,diogomg/olsrd-binary-heap,duydb2/olsr,ralisi/olsrd_cl_roam,diogomg/olsrd,servalproject/olsr,diogomg/olsrd,duydb2/olsr,brabander/olsr,sebkur/olsrd,cholin/olsrd,acinonyx/olsrd,nolith/olsrd,sebkur/olsrd,brabander/olsr