workaround for iD bug #10761

the current version of iD (v2.31, before the fix for https://github.com/openstreetmap/iD/issue/10761: https://github.com/openstreetmap/iD/pull/10766), does not fully support `x-www-form-urlencoded` "query-style" strings in the hash: Specifically, spaces encoded as `+` will not be decoded back to ` `.

This workaround essentially temporarily reverts the behaviour of the website to the state before #5592, and can be dropped again with the next minor version upgrade of iD (`v2.32`).