Make sure BA-IND in all SI2xxx is '0' and in all SI5xxx is '1'

In masurement reports sent by the MS, this can then be used to correlate
if a given measurement report was in response to a BCCH/neighbor list
received on BCCH (SI2xxx) or on dowlink SACCH (SI5xxx).

Closes: OS#2525
Change-Id: I1cd0dc51026dcd0e508e63eea4e333e6b184787a
diff --git a/src/libbsc/rest_octets.c b/src/libbsc/rest_octets.c
index 866734b..09c4a90 100644
--- a/src/libbsc/rest_octets.c
+++ b/src/libbsc/rest_octets.c
@@ -361,8 +361,12 @@
 	bv.data_len = 20;
 	bitvec_zero(&bv);
 
-	/* BA_IND */
-	bitvec_set_bit(&bv, 1);
+	/* BA_IND: Set to '0' as that's what we use for SI2xxx type,
+	 * whereas '1' is used for SI5xxx type messages. The point here
+	 * is to be able to correlate whether a given MS measurement
+	 * report was using the neighbor cells advertised in SI2 or in
+	 * SI5, as those two could very well be different */
+	bitvec_set_bit(&bv, 0);
 	/* 3G_BA_IND */
 	bitvec_set_bit(&bv, 1);
 	/* MP_CHANGE_MARK */