Fix error in call reference conversion to string.

  src/ftmod/ftmod_sangoma_ss7/ftmod_sangoma_ss7_handle.c
  cc1: warnings being treated as errors
  src/ftmod/ftmod_sangoma_ss7/ftmod_sangoma_ss7_handle.c: In function
  'handle_con_ind':
  src/ftmod/ftmod_sangoma_ss7/ftmod_sangoma_ss7_handle.c:255: warning: format '%x'
  expects type 'unsigned int', but argument 3 has type 'U32'
  make[6]: *** [ftmod_sangoma_ss7_la-ftmod_sangoma_ss7_handle.lo] Error 1

libs/freetdm/src/ftmod/ftmod_sangoma_ss7/ftmod_sangoma_ss7_handle.c

@@ -252,7 +252,9 @@ ftdm_status_t handle_con_ind(uint32_t suInstId, uint32_t spInstId, uint32_t circ
 			sngss7_add_var(sngss7_info, "ss7_opc", var);
 			
 			if (siConEvnt->callRef.callId.pres) {
-				sprintf(var, "%x", siConEvnt->callRef.callId.val);
+        /* %x expect an unsigned int so as callId is a U32, casting to uint32_t
+         * is safe */
+				sprintf(var, "%x", (uint32_t)siConEvnt->callRef.callId.val);
 				sngss7_add_var(sngss7_info, "ss7_callref", var);
 			}