'Hide Whitespace Changes' checkbox has no effect, must refresh page to see result

Repro

1. Open Merge Request
2. Toggle the Show Whitespace Changes checkbox

Expected: whitespace changes are shown/hidden Actual: ?w=0/?w=1 query parameter in the page URL is toggled, but the code view doesn't actually update unless page is refreshed.

repro

Environment

• GitLab 11.8.7-ee
• Chrome 75.0.3770.100
• macOS 10.14.4