MR diffs page: Show whitespace changes is rendered when the url ends on ?w=0

Summary

Show whitespace changes is rendered on the MR diffs page when the page url ends on ?w=0. Clicking the button results in the page being reloaded with ?w=0

Probably related to gitlab-ce#48654.

Steps to reproduce

smcgivern/gitlab-test!2 (diffs)

What is the current bug behavior?

Show whitespace changes is rendered and clicking it results in the page being reloaded with ?w=0

What is the expected correct behavior?

Hide whitespace changes is rendered and clicking it results in the page being reloaded with ?w=1

Relevant logs and/or screenshots

Output of checks

This bug happens on GitLab.com

Possible fixes

https://gitlab.com/gitlab-org/gitlab-ce/blob/e23b966d8dd2a161d3493c0b991c0c2ce43fea75/app/assets/javascripts/diffs/components/changed_files.vue#L34 This probably needs additional check for value 0:

    whitespaceVisible() {
      var whitespaceVisible = getParameterValues('w')[0]
      return !whitespaceVisible || whitespaceVisible === "0"
    },

I can create a MR if needed.