git-instaweb: Fix custom apache log placement

'CustomLog' is provided by mod_log_config so we need to include the module
in our generated config. This was added in d94775e.

Signed-off-by: Dan McGee <dpmcgee@gmail.com>
Acked-by: Eric Wong <normalperson@yhbt.net>

git-instaweb.sh

@@ -314,7 +314,7 @@ PidFile "$fqgitdir/pid"
 Listen $bind$port
 EOF
 
-	for mod in mime dir; do
+	for mod in mime dir log_config; do
 		if test -e $module_path/mod_${mod}.so; then
 			echo "LoadModule ${mod}_module " \
 			     "$module_path/mod_${mod}.so" >> "$conf"