urlmon: Fix the MIME type reported by the HTTP protocol when the Content-Type headers contains charset data too.

[Misha Koshelev]

Sorry to send this out after the patch has already been committed, but
this patch is wrong. If you just output the Content-Type in
test/protocol.c you'll see that the charset data is included in the
"MIME type" in both Windows XP and on wine with native urlmon (from
WinME or 98; I believe the XP one crashes wine or at least it used to).
That is why when I was fixing the original test I just changed it to a
memcmp from a strcmp.

Misha