ims_usrloc_scscf:bugfix erraneous unlinking of deleted contact

impurecord.c: corrected small bug in remove_impucontact_from_list()

src/modules/ims_usrloc_scscf/impurecord.c

@@ -1102,10 +1102,11 @@ int remove_impucontact_from_list(impurecord_t* impu, impu_contact_t *impucontact
 	} else if (contact == impu->linked_contacts.tail->contact) {
 		LM_DBG("deleting tail\n");
 		impu->linked_contacts.tail = impu->linked_contacts.tail->prev;
+                impu->linked_contacts.tail->next = 0;
 	} else {
 		LM_DBG("deleting mid list\n");
 		impucontact->prev->next = impucontact->next;
-		impucontact->prev = impucontact->next->prev;
+		impucontact->next->prev = impucontact->prev;
 	}
 	
 	impu->linked_contacts.numcontacts--;