refactor(http-loader): update http-loader

** PR Checklist Please check if your PR fulfills the following requirements:

[x] The commit message follows our guidelines: https://github.com/fulls1z3/ngx-i18n-router/blob/master/CONTRIBUTING.md#commit
[x] Tests for the changes have been added (for bug fixes / features)
[ ] Docs have been added / updated (for bug fixes / features)

** PR Type What kind of change does this PR introduce?

[ ] Bugfix
[ ] Feature
[ ] Code style update (formatting, local variables)
[x] Refactoring (no functional changes, no api changes)
[x] Build related changes
[ ] CI related changes
[ ] Documentation content changes
[ ] Other... Please describe:

** What is the current behavior?

Issue Number: N/A

** What is the new behavior?

** Does this PR introduce a breaking change?

[ ] Yes
[x] No

** Other information

fulls1z3 / ngx-i18n-router

refactor(http-loader): update http-loader #32