Avoid displaying the translation banner

[jonkri]

Here's a suggestion to avoid displaying the translation banner as discussed here. We've been disabling the translation banner for about one and a half years in Sweden and no one has complained.

• [ ] Has the code POD documentation been added or updated?
• [ ] Whether this PR should include changes to any public documentation, or the FAQ;
• [x] All cobrand-specific commits start their commit message with the cobrand in square brackets;
• [ ] Is new functionality tested? CodeCov will warn you about the diff coverage, but won’t complain about e.g. new files;
• [ ] Will cobrand-specific changes require additional work to ensure consistent behaviour on www.fixmystreet.com?
• [ ] Are the changes tested for accessibility?
• [x] Have you updated the changelog? If this is not necessary, put square brackets around this: skip changelog

[dracos]

I have merged this as ecde96bc08e7cf94469b57af6bbdaf4c5c5c9aca - I put the line a bit higher up in the file, alongside the "don't detect telephone numbers" which seemed to be in vaguely the same sort of area.