[#3784]fix HttpUtils cannot correctly resolve file names (#3801)

[liubao68]

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[codecov-commenter]

Codecov Report

Merging #3809 (ccfff8a) into 2.8.x (be3ab60) will increase coverage by 0.01%.
The diff coverage is 100.00%.

❗ Current head ccfff8a differs from pull request most recent head 375dd34. Consider uploading reports for the commit 375dd34 to get more accurate results

@@             Coverage Diff              @@
##              2.8.x    #3809      +/-   ##
============================================
+ Coverage     74.43%   74.44%   +0.01%     
  Complexity      689      689              
============================================
  Files          1592     1592              
  Lines         39982    39982              
  Branches       3650     3650              
============================================
+ Hits          29761    29766       +5     
+ Misses         8733     8730       -3     
+ Partials       1488     1486       -2     

Impacted Files	Coverage Δ
.../servicecomb/foundation/common/http/HttpUtils.java	94.59% <100.00%> (ø)

... and 4 files with indirect coverage changes

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