Initialize locale directory for tests

Since commit a7865ef5

 (Make the locale directory configurable,
2018-07-22), we need to specify the locale directory in the
configuration file.
Signed-off-by: Lukas Fleischer <lfleischer@archlinux.org>

test/setup.sh

@@ -31,6 +31,7 @@ aur_request_ml = aur-requests@archlinux.org
 enable-maintenance = 0
 maintenance-exceptions = 127.0.0.1
 commit_uri = https://aur.archlinux.org/cgit/aur.git/log/?h=%s&id=%s
+localedir = $TOPLEVEL/web/locale/
 
 [notifications]
 notify-cmd = $NOTIFY