git-instaweb: unconditionally assume that gitweb is mod_perl capable

Remove a check for whether mod_perl is a supported mode of gitweb.cgi
added in a51d37c1df (Add git-instaweb, instantly browse the working
repo with gitweb, 2006-07-01).

The reason for the check was to support users who had a newer version
of git and an older version of gitweb, it was then subsequently
adjusted for changes in the script in f0e588dffc (git-instaweb: fix
mod_perl detection for apache2, 2009-08-08).

It's a fair bet that nobody's running a git from 2021 and gitweb from
pre-2007 anymore, so we can unconditionally assume that this will be
supported by gitweb.cgi.

This allows a subsequent commit to remove the sane_grep() wrapper,
this change is split up from that since this is the only case where
the "grep" invocation could be removed entirely.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

git-instaweb.sh

@@ -380,10 +380,7 @@ TypesConfig "$fqgitdir/mime.types"
 DirectoryIndex gitweb.cgi
 EOF
 
-	# check to see if Dennis Stosberg's mod_perl compatibility patch
-	# (<20060621130708.Gcbc6e5c@leonov.stosberg.net>) has been applied
-	if test -f "$module_path/mod_perl.so" &&
-	   sane_grep 'MOD_PERL' "$root/gitweb.cgi" >/dev/null
+	if test -f "$module_path/mod_perl.so"
 	then
 		# favor mod_perl if available
 		cat >> "$conf" <<EOF