Don't report messages with only a single reference in xtreport.

src/xtreport.c

@@ -181,12 +181,13 @@ void xtreport(void)
 	struct mosquitto_msg_store *msg_store, *msg_store_tmp;
 
 	HASH_ITER(hh, db.msg_store, msg_store, msg_store_tmp){
+		if(msg_store->ref_count > 1){
 			fprintf(fptr, "cfn=(%d) %" PRIu64 "\n", fn_index_max, msg_store->db_id);
 			fprintf(fptr, "calls=%d %d\n", msg_store->ref_count, fn_index_max);
 			fprintf(fptr, "%d 0 0 0 0 0 0 0 %d 0 0 0\n", fn_index_max, msg_store->ref_count);
-
 			fn_index_max++;
 		}
+	}
 
 	fclose(fptr);
 }