Fix #1962: Scrollable Language Menu (#1965)
Fix #1962: Scrollable Language Menu (#1965)

updated max-width to use vh unit
humphd/thimble.mozilla.org,mozilla/thimble.mozilla.org,humphd/thimble.mozilla.org,humphd/thimble.mozilla.org,humphd/thimble.mozilla.org,mozilla/thimble.mozilla.org,mozilla/thimble.mozilla.org,mozilla/thimble.mozilla.org