Also force LC_ALL in test scripts.

Noticed by Junichi Uekawa.

Signed-off-by: Junio C Hamano <junkio@cox.net>

t/test-lib.sh

@@ -5,9 +5,10 @@
 
 # For repeatability, reset the environment to known value.
 LANG=C
+LC_ALL=C
 PAGER=cat
 TZ=UTC
-export LANG PAGER TZ
+export LANG LC_ALL PAGER TZ
 unset AUTHOR_DATE
 unset AUTHOR_EMAIL
 unset AUTHOR_NAME