test: add unit-test for hasPort method

[forienlauo]

Ⅰ. Describe what this PR did

#1641: add unit-test for hasPort method

Ⅱ. Does this pull request fix one issue?

NONE

Ⅲ. Describe how you did it

NONE

Ⅳ. Describe how to verify it

NONE

Ⅴ. Special notes for reviews

NONE

[CLAassistant]

All committers have signed the CLA.

[pouchrobot]

We found this is your first time to contribute to Pouch, @forienlauo
👏 We really appreciate it.
Just remind that you have read the contribution guide: https://github.com/alibaba/pouch/blob/master/CONTRIBUTING.md
If you didn't, you should do that first. If done, welcome again and please enjoy hacking! 🍻

[codecov-io]

Codecov Report

Merging #1654 into master will decrease coverage by 0.02%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #1654      +/-   ##
==========================================
- Coverage   41.16%   41.14%   -0.03%     
==========================================
  Files         274      274              
  Lines       18091    18091              
==========================================
- Hits         7447     7443       -4     
- Misses       9729     9734       +5     
+ Partials      915      914       -1

Impacted Files	Coverage Δ
ctrd/image.go	75.27% <0%> (-2.75%)	⬇️
daemon/mgr/system.go	75% <0%> (-1.73%)	⬇️
ctrd/image_proxy_util.go	9.37% <0%> (+1.56%)	⬆️
daemon/logger/jsonfile/utils.go	73.17% <0%> (+1.62%)	⬆️

[allencloud]

Oh, actually this is pr which does the same thing as #1668. But this is much better I think. In addition this is done much earlier. What should we do? @HusterWan @fuweid

[allencloud]

LGTM