Build proper url instead of interpolating in Puma::DSL#port

[ojab]

Description

Fixes the issue with running puma handler with Host: '::1', right now we have a backtrace, since [::1] should be used as a hostname in URIs.

$ bundle exec rails s -u puma -b '::1'
=> Booting Puma
=> Rails 6.0.3.4 application starting in development
=> Run `rails server --help` for more startup options
Puma starting in single mode...
* Puma version: 5.1.1 (ruby 2.7.2-p137) ("At Your Service")
*  Min threads: 5
*  Max threads: 5
*  Environment: development
*          PID: 9014
Exiting
Traceback (most recent call last):
…
	10: from /home/ojab/.rbenv/versions/2.7.2/lib/ruby/gems/2.7.0/gems/rack-2.2.3/lib/rack/server.rb:327:in `start'
	 9: from /home/ojab/.rbenv/versions/2.7.2/lib/ruby/gems/2.7.0/gems/puma-5.1.1/lib/rack/handler/puma.rb:71:in `run'
	 8: from /home/ojab/.rbenv/versions/2.7.2/lib/ruby/gems/2.7.0/gems/puma-5.1.1/lib/puma/launcher.rb:182:in `run'
	 7: from /home/ojab/.rbenv/versions/2.7.2/lib/ruby/gems/2.7.0/gems/puma-5.1.1/lib/puma/single.rb:44:in `run'
	 6: from /home/ojab/.rbenv/versions/2.7.2/lib/ruby/gems/2.7.0/gems/puma-5.1.1/lib/puma/runner.rb:144:in `load_and_bind'
	 5: from /home/ojab/.rbenv/versions/2.7.2/lib/ruby/gems/2.7.0/gems/puma-5.1.1/lib/puma/binder.rb:152:in `parse'
	 4: from /home/ojab/.rbenv/versions/2.7.2/lib/ruby/gems/2.7.0/gems/puma-5.1.1/lib/puma/binder.rb:152:in `each'
	 3: from /home/ojab/.rbenv/versions/2.7.2/lib/ruby/gems/2.7.0/gems/puma-5.1.1/lib/puma/binder.rb:153:in `block in parse'
	 2: from /home/ojab/.rbenv/versions/2.7.2/lib/ruby/2.7.0/uri/common.rb:234:in `parse'
	 1: from /home/ojab/.rbenv/versions/2.7.2/lib/ruby/2.7.0/uri/rfc3986_parser.rb:73:in `parse'
/home/ojab/.rbenv/versions/2.7.2/lib/ruby/2.7.0/uri/rfc3986_parser.rb:67:in `split': bad URI(is not URI?): "tcp://::1:3000" (URI::InvalidURIError)

Your checklist for this pull request

• I have reviewed the guidelines for contributing to this repository.
• I have added an entry to History.md if this PR fixes a bug or adds a feature. If it doesn't need an entry to HISTORY.md, I have added [changelog skip] or [ci skip] to the pull request title.
• I have added appropriate tests if this PR fixes a bug or adds a feature.
• My pull request is 100 lines added/removed or less so that it can be easily reviewed.
• If this PR doesn't need tests (docs change), I added [ci skip] to the title of the PR.
• If this closes any issues, I have added "Closes #issue" to the PR description or my commit messages.
• I have updated the documentation accordingly.
• All new and existing tests passed, including Rubocop.

[ojab]

CI failures seems unerlated.

[nateberkopec]

Cheers, makes sense. Needs a History.md entry.

[ojab]

:okay:, History.md entry added.

[nateberkopec]

Thanks so much @ojab, welcome to the Puma contributor family 🤗