Merge pull request #7992 from taosdata/hotfix/TD-7515

[td-7515]fix taos crash issue

src/kit/shell/src/shellImport.c

@@ -210,7 +210,7 @@ static void shellSourceFile(TAOS *con, char *fptr) {
     /* free local resouce: allocated memory/metric-meta refcnt */
     taos_free_result(pSql);
 
-    memset(cmd, 0, MAX_COMMAND_SIZE);
+    memset(cmd, 0, tsMaxSQLStringLen);
     cmd_len = 0;
   }