e1_input: Add E1 timeslot number to input_signal_data

It is quite useful for the signal receiver to know on which of the many
E1/T1 timeslots a given event (like a 'link down' event) has happened.
The line number, TEI and SAPI are isnuficcient in case there are
multiple signalling TS in the line.

Change-Id: I07f0f79e0cda09766f357032ffb4e7ad643d448a
diff --git a/src/input/dahdi.c b/src/input/dahdi.c
index 9f1f2bb..ab06908 100644
--- a/src/input/dahdi.c
+++ b/src/input/dahdi.c
@@ -139,6 +139,7 @@
 		get_value_string(dahdi_evt_names, evt));
 
 	isd.line = ts->line;
+	isd.ts_nr = ts->num;
 
 	switch (evt) {
 	case DAHDI_EVENT_ALARM: