fix json tag can not export to file

src/kit/shell/src/shellEngine.c

@@ -501,6 +501,7 @@ static void dumpFieldToFile(FILE* fp, const char* val, TAOS_FIELD* field, int32_
       break;
     case TSDB_DATA_TYPE_BINARY:
     case TSDB_DATA_TYPE_NCHAR:
+    case TSDB_DATA_TYPE_JSON:
       memcpy(buf, val, length);
       buf[length] = 0;
       fprintf(fp, "\'%s\'", buf);