user-manual: Fix 'http' -> 'HTTP' typos
user-manual: Fix 'http' -> 'HTTP' typos

HTTP is an acronym which has not (yet) made the transition to word
status (unlike "laser", probably because lasers are inherently cooler
than HTTP ;).

Signed-off-by: W. Trevor King <f75897670c17327c42ab201733fb8a81ff9f4c34@tremily.us>
Signed-off-by: Junio C Hamano <a6723cc3f76163bf7adb636a73ac3b0ceb3e6b9b@pobox.com>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git