search: cannot search on iOS

[mikix]

To reproduce:

• Open flathub.org on iOS (I tried with both Safari and Firefox)
• Click the magnifying glass
• Click the search bar
• Enter a phrase
• Press “return” on the on-screen keyboard

Nothing happens. But I would expect to be brought to a search results page.

This may happen on all mobile platforms, I don’t know. I only have iOS to test on.