topo_node_sqlite: dynamic idx_sql allocation instead of fixed 128-byte buffer

src/routing_layer/topo_node_sqlite.c

@@ -278,10 +278,15 @@ int topo_node_sqlite_channel_put(sqlite3* db, const char* channel_id,
         u_free(ddl);
     }
 
-    char idx_sql[128];
-    snprintf(idx_sql, sizeof(idx_sql),
+    int idx_sz = snprintf(NULL, 0,
         "CREATE INDEX IF NOT EXISTS \"idx_%s_type_rtt\" ON \"%s\" (node_type, node_RTT)", peers_tbl, peers_tbl);
-    sqlite3_exec(db, idx_sql, NULL, NULL, NULL);
+    char* idx_sql = u_malloc(idx_sz + 1);
+    if (idx_sql) {
+        snprintf(idx_sql, idx_sz + 1,
+            "CREATE INDEX IF NOT EXISTS \"idx_%s_type_rtt\" ON \"%s\" (node_type, node_RTT)", peers_tbl, peers_tbl);
+        sqlite3_exec(db, idx_sql, NULL, NULL, NULL);
+        u_free(idx_sql);
+    }
 
     sqlite3_stmt* stmt = NULL;
     if (sqlite3_prepare_v2(db,