sgsn: Change the selection mode to verified

We have verified/selected the APN. Either based on the subscriber
data, a global APN match. But at least this SGSN has looked at
what the MS has asked for and then selected a matching GGSN.
diff --git a/openbsc/src/gprs/sgsn_libgtp.c b/openbsc/src/gprs/sgsn_libgtp.c
index 19c46b7..6aa12b2 100644
--- a/openbsc/src/gprs/sgsn_libgtp.c
+++ b/openbsc/src/gprs/sgsn_libgtp.c
@@ -153,8 +153,8 @@
 	pdp->hisaddr1 = ggsn->remote_addr;
 	//pdp->cch_pdp = 512;	/* Charging Flat Rate */
 
-	/* MS provided APN, subscription not verified */
-	pdp->selmode = 0xFC | 0x01;
+	/* MS provided APN, subscription was verified by the caller */
+	pdp->selmode = 0xFC | 0x00;
 
 	/* IMSI, TEID/TEIC, FLLU/FLLC, TID, NSAPI set in pdp_newpdp */