Avoid duplicate scheme declaration when using proxy with SSL

[jmcnatt]

Pull Request (PR) description

• Added negation logic when scheme key is present when iterating through the proxy hash.
• Added additional test for tomcat_native_ssl without proxy settings.

This Pull Request (PR) fixes the following issues

Fixes #395

[root-expert]

I think the actual fix for this to add a ! in the condition here.

In fact, that was the case before the template was converted to epp and by accident ! was removed.

References, here and here

Can you also rebase with master branch to fix conflicts and the failing specs?
Adding some specs for this so it won't break in the future would be awesome!

[jmcnatt]

Makes sense! I'll rebase, update the PR, and see if I can author a spec for this condition.

[jmcnatt]

Updated the PR to use the ! logic instead of unless.

I was able to write a spec context for specifying tomcat_native_ssl: true with and without proxy. Looking for duplicate scheme="https" may be difficult without checking for exact contents of the entire file (at least when using with_content()).

[root-expert]

Hello, please perform a rebase instead of a merge commit 😄

[jmcnatt]

I rebased and removed the spacing and quotation change.

[root-expert]

Please squash your commits before we merged this 😄

And thanks for the contribution!