Add missing "HTTP_HOST" in wordpress-fpm-run test

This avoids the following warning:

    PHP message: PHP Warning:  Undefined array key "HTTP_HOST" in /var/www/html/wp-includes/functions.php on line 5880

test/tests/wordpress-fpm-run/run.sh

@@ -42,6 +42,7 @@ fcgi-request() {
 		-e SCRIPT_NAME="$url" \
 		-e SCRIPT_FILENAME=/var/www/html/"${url#/}" \
 		-e QUERY_STRING="$queryString" \
+		-e HTTP_HOST='localhost' \
 		"$clientImage" \
 		-bind -connect fpm:9000
 }