fix acs_request.go map in struct request

[King-Hell]

ECI团队提交：增加对于struct嵌套map格式request的支持，用以支持ECI DataCache API上线

[CLAassistant]

All committers have signed the CLA.

[codecov-commenter]

Codecov Report

Merging #597 (da51ff3) into master (9a572a8) will decrease coverage by 0.34%. The diff coverage is 0.00%.

:exclamation: Current head da51ff3 differs from pull request most recent head 03607a3. Consider uploading reports for the commit 03607a3 to get more accurate results

@@            Coverage Diff             @@
##           master     #597      +/-   ##
==========================================
- Coverage   93.57%   93.24%   -0.34%     
==========================================
  Files          48       48              
  Lines        2538     2547       +9     
==========================================
  Hits         2375     2375              
- Misses        106      114       +8     
- Partials       57       58       +1     

Files	Coverage Δ
sdk/requests/acs_request.go	78.11% <0.00%> (-2.75%)	:arrow_down:

[JacksonTian]

@King-Hell 需要一个单元测试来覆盖这部分代码。