BUG/MINOR: http: remove stupid HTTP_METH_NONE entry

BUG/MINOR: http: remove stupid HTTP_METH_NONE entry

When converting the "method" fetch to a string, we used to get an empty
string if the first character was not an upper case. This was caused by
the lookup function which returns HTTP_METH_NONE when a lookup is not
possible, and this method being mapped to an empty string in the array.

This is a totally stupid mechanism, there's no reason for having the
result depend on the first char. In fact the message parser already
checks that the syntax matches an HTTP token so we can only land there
with a valid token, hence only HTTP_METH_OTHER should be returned.

This fix should be backported to all actively supported branches.