Midori sends capitalized http[s] uris to external handler

[gue5t gue5t]

To reproduce: enter HTTPS://example.com/ or HTTP://example.com/ in the address bar. Any capitalization other than all-lowercase will cause an external program (such as another instance of midori, or the default system browser) to open the URI.

This is probably something being case-sensitive in sokoke, but IIRC there are a lot of places where we compare against a literal "http" string which should probably be factored out to ensure consistency.