Use 04.08 IMM ASS REJECT in case we run out of channels

If the user has a non-zero 'timer t3122' in the config file, we will
send an IMM ASS REJECT in case we run out of resources.
diff --git a/openbsc/src/bsc_vty.c b/openbsc/src/bsc_vty.c
index a0c19b7..c293433 100644
--- a/openbsc/src/bsc_vty.c
+++ b/openbsc/src/bsc_vty.c
@@ -547,6 +547,7 @@
 	vty_out(vty, " timer t3115 %u%s", gsmnet->T3115, VTY_NEWLINE);
 	vty_out(vty, " timer t3117 %u%s", gsmnet->T3117, VTY_NEWLINE);
 	vty_out(vty, " timer t3119 %u%s", gsmnet->T3119, VTY_NEWLINE);
+	vty_out(vty, " timer t3122 %u%s", gsmnet->T3122, VTY_NEWLINE);
 	vty_out(vty, " timer t3141 %u%s", gsmnet->T3141, VTY_NEWLINE);
 	vty_out(vty, " dtx-used %u%s", gsmnet->dtx_enabled, VTY_NEWLINE);
 
@@ -1323,6 +1324,7 @@
 DECLARE_TIMER(3115, "Currently not used.")
 DECLARE_TIMER(3117, "Currently not used.")
 DECLARE_TIMER(3119, "Currently not used.")
+DECLARE_TIMER(3122, "Waiting time (seconds) after IMM ASS REJECT")
 DECLARE_TIMER(3141, "Currently not used.")
 
 DEFUN(cfg_net_dtx,