cosmetic: Move comment one line below in append_gprs_cell_opt

Move it above the place where the bit is set, since the bit represents
whether Extension Information is available, not whether R99 is
available.

Change-Id: Ice592acc50a24efd7fe4cf1a91f1d48fd74f38d8
diff --git a/src/gsm/gsm48_rest_octets.c b/src/gsm/gsm48_rest_octets.c
index f45e818..1bab8e0 100644
--- a/src/gsm/gsm48_rest_octets.c
+++ b/src/gsm/gsm48_rest_octets.c
@@ -906,9 +906,8 @@
 		bitvec_set_bit(bv, 0);
 	} else {
 		/* extension information */
-
-		/* R99 extension: */
 		bitvec_set_bit(bv, 1);
+		/* R99 extension: */
 		if (!gco->ext_info.egprs_supported) {
 			/* 6bit length of extension */
 			bitvec_set_uint(bv, (1 + 5)-1, 6);