Drop system includes from inet_pton/inet_ntop compatibility wrappers
As both of these compatibility wrappers include git-compat-utils.h,
all of the system includes were redundant.
Dropping these system includes also makes git-compat-utils.h the first
include which avoids a compiler warning on Solaris due to the
redefinition of _FILE_OFFSET_BITS.
Signed-off-by: Ben Walton <bwalton@artsci.utoronto.ca> Signed-off-by: Junio C Hamano <gitster@pobox.com>