Fix es_scan_reader_test in debug mode

[kangkaisen]

es_scan_reader_test: /home/kangkaisen/palo/thirdparty/installed/include/rapidjson/document.h:1053: rapidjson::GenericValue<Encoding, Allocator>& rapidjson::GenericValue<Encoding, Allocator>::operator[](const rapidjson::GenericValue<Encoding, SourceAllocator>&) [with SourceAllocator = rapidjson::MemoryPoolAllocator<>; Encoding = rapidjson::UTF8<>; Allocator = rapidjson::MemoryPoolAllocator<>]: Assertion `false' failed.
run-ut.sh: line 140: 194835 Aborted                 (core dumped) ${DORIS_TEST_BINARY_DIR}/exec/es_scan_reader_test

The mock_es_server response:

{"_scroll_id":"1","hits":{"total":10,"hits":[{"id":1,"value":"1"}]}}
{"_scroll_id":"2","hits":{"total":10,"hits":[{"id":2,"value":"2"}]}}
{"_scroll_id":"3","hits":{"total":10,"hits":[{"id":3,"value":"3"}]}}
{"_scroll_id":"4","hits":{"total":10,"hits":[{"id":4,"value":"4"}]}}
{"_scroll_id":"5","hits":{"total":10,"hits":[{"id":5,"value":"5"}]}}
{"_scroll_id":"6","hits":{"total":10,"hits":[{"id":6,"value":"6"}]}}
{"_scroll_id":"7","hits":{"total":10,"hits":[{"id":7,"value":"7"}]}}
{"_scroll_id":"8","hits":{"total":10,"hits":[{"id":8,"value":"8"}]}}
{"_scroll_id":"9","hits":{"total":10,"hits":[{"id":9,"value":"9"}]}}
{"_scroll_id":"10","hits":{"total":10,"hits":[{"id":10,"value":"10"}]}}
{"_scroll_id":"11","hits":{"total":10,"hits":[{"id":11,"value":"11"}]}}
{"_scroll_id":"11","hits":{"total":10}}

[imay]

LGTM