git p4 test: sanitize P4CHARSET

In the tests, p4d is started without using "internationalized
mode".  Make sure this environment variable is unset, otherwise
a mis-matched user setting would break the tests.  The error
message would be "Unicode clients require a unicode enabled server."

[pw: use unset, add commit text]

Signed-off-by: Kazuki Saitoh <ksaitoh560@gmail.com>
Signed-off-by: Pete Wyckoff <pw@padd.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/lib-git-p4.sh

@@ -48,7 +48,8 @@ P4DPORT=$((10669 + ($testid - $git_p4_test_start)))
 P4PORT=localhost:$P4DPORT
 P4CLIENT=client
 P4EDITOR=:
-export P4PORT P4CLIENT P4EDITOR
+unset P4CHARSET
+export P4PORT P4CLIENT P4EDITOR P4CHARSET
 
 db="$TRASH_DIRECTORY/db"
 cli="$TRASH_DIRECTORY/cli"