Permit any Sender MSISDN when sending SMS from VTY

In the old days, OsmoNITB couldn't process any SMS that wasn't between
two subscribers on the same NITB.

We've long re-worked the internals in order to process SMS with
arbitrary sender MSISDN (e.g. from SMPP). However, the VTY command
"subscriber ... sms" was never updated, it seems.

Change-Id: I62b17e0a67989484415f0df2c8cb4ff1f94dbf2b
Closes: OS#3151
diff --git a/src/libmsc/gsm_04_11.c b/src/libmsc/gsm_04_11.c
index aa60490..077c8d8 100644
--- a/src/libmsc/gsm_04_11.c
+++ b/src/libmsc/gsm_04_11.c
@@ -82,7 +82,7 @@
 }
 
 struct gsm_sms *sms_from_text(struct vlr_subscr *receiver,
-			      struct vlr_subscr *sender,
+			      const char *sender_msisdn,
                               int dcs, const char *text)
 {
 	struct gsm_sms *sms = sms_alloc();
@@ -93,7 +93,7 @@
 	sms->receiver = vlr_subscr_get(receiver);
 	OSMO_STRLCPY_ARRAY(sms->text, text);
 
-	OSMO_STRLCPY_ARRAY(sms->src.addr, sender->msisdn);
+	OSMO_STRLCPY_ARRAY(sms->src.addr, sender_msisdn);
 	sms->reply_path_req = 0;
 	sms->status_rep_req = 0;
 	sms->ud_hdr_ind = 0;