Place charset in the default configuration file

src/system/CMakeLists.txt

@@ -19,6 +19,7 @@ ADD_CUSTOM_COMMAND(OUTPUT ${PREPARE_ENV_CMD}
   COMMAND ${CMAKE_COMMAND} -E make_directory ${TESTS_OUTPUT_DIR}/data/
   COMMAND ${CMAKE_COMMAND} -E echo dataDir ${TESTS_OUTPUT_DIR}/data > ${TESTS_OUTPUT_DIR}/cfg/taos.cfg
   COMMAND ${CMAKE_COMMAND} -E echo logDir ${TESTS_OUTPUT_DIR}/log  >> ${TESTS_OUTPUT_DIR}/cfg/taos.cfg
+  COMMAND ${CMAKE_COMMAND} -E echo charset UTF-8  >> ${TESTS_OUTPUT_DIR}/cfg/taos.cfg
   COMMENT "prepare taosd environment")
 ADD_CUSTOM_TARGET(${PREPARE_ENV_TARGET} ALL WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH} DEPENDS ${PREPARE_ENV_CMD})