tm: use the new function for 200ok Via branch of local transactions

src/modules/tm/t_msgbuilder.c

@@ -1321,7 +1321,7 @@ char *build_dlg_ack(struct sip_msg *rpl, struct cell *Trans,
 	}
 
 	/* via */
-	if(!t_calc_branch(Trans, branch, branch_buf, &branch_len))
+	if(!t_calc_branch_ack(Trans, branch, branch_buf, &branch_len))
 		goto error;
 	branch_str.s = branch_buf;
 	branch_str.len = branch_len;

src/modules/tm/t_msgbuilder.h

@@ -71,6 +71,8 @@ char *build_uac_req(str *method, str *headers, str *body, dlg_t *dialog,
 
 int t_calc_branch(struct cell *t, int b, char *branch, int *branch_len);
 
+int t_calc_branch_ack(struct cell *t, int b, char *branch, int *branch_len);
+
 /* exported minimum functions for use in t_cancel */
 char *print_callid_mini(char *target, str callid);
 char *print_cseq_mini(char *target, str *cseq, str *method);