Fix exit status when rubocop is interrupted

[deivid-rodriguez]

I wanted to resume the work I started on #5808, but I noticed a small issue with the status code rubocop has when interrupted. If you type Ctrl-C while rubocop is running, it will have an exit status of "1", which in rubocop's domain means "offenses were detected". However, this is not accurate since one may interrupt rubocop without any offenses having yet been detected (for example, because it will take too long to run).

So I changed the status code in this situation to be 130, which is a common practice for scripts. See for example https://stackoverflow.com/a/40484670/143243.

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Before submitting the PR make sure the following are checked:

• Wrote good commit messages.
• Commit message starts with [Fix #issue-number] (if the related issue exists).
• Feature branch is up-to-date with master (if not - rebase it).
• Squashed related commits together.
• Added tests.
• Added an entry to the Changelog if the new code introduces user-observable changes. See changelog entry format.
• The PR relates to only one subject with a clear title
  and description in grammatically correct, complete sentences.
• Run rake default. It executes all tests and RuboCop for itself, and generates the documentation.

[koic]

Superb! Thanks a lot.

[deivid-rodriguez]

Thanks to you! 👍