Fix process exit not working on Windows

[xuchaoying]

• Please check if the PR fulfills these requirements

• The commit message follows our guidelines
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

• What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)

bug fix

• What is the related issue? (Use #issue_id to relate an open issue)

#127

• Does this PR introduce a breaking change?

no

• Other information:

[codecov]

Codecov Report

Merging #132 into master will increase coverage by 0.02%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #132      +/-   ##
==========================================
+ Coverage   92.18%   92.21%   +0.02%     
==========================================
  Files          44       44              
  Lines        1599     1605       +6     
==========================================
+ Hits         1474     1480       +6     
  Misses        125      125

Impacted Files	Coverage Δ
packages/svrx/index.js	100% <100%> (ø)	⬆️

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