ipaccess: add bugtrag for the RSL link becomes up case
ipaccess: add bugtrag for the RSL link becomes up case

The RSL signal link becomes up for the ipaccess driver is tricky.
If the BSC forgets to use the E1 line used by OML for the RSL
link, we run into trouble.

This patch adds a bugtrap so people don't forget to appropriately
handle this case.

osmobuntu/libosmo-abis,osmobuntu/libosmo-abis,osmocom/libosmo-abis,osmocom/libosmo-abis,osmobuntu/libosmo-abis,osmobuntu/libosmo-abis,osmocom/libosmo-abis,telenoobie/libosmo-abis,telenoobie/libosmo-abis