Urlencode the redis password in the cache URI

[cincodenada]

This should fix #1790 where we had issues if passwords have non-URL-safe characters in them

[cincodenada]

Again, I still need to actually test this one fully, so don't merge quite yet :)

[mouse-reeve]

I tested this out with a password with ? in it, and on main I get a weird error about the port as a result of the url encoding issue, which was fixed by this code change. But I still got a WRONGPASS error on this branch; I manually authenticated in redis-cli with the password successfully so I think there may be an encoding issue with using the password, even though the urlencode fixes the LOCATION field syntax.