Fix httpd tests that broke when non-ff push advice changed

Signed-off-by: Christopher Tiwald <christiwald@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/lib-httpd.sh

@@ -160,6 +160,6 @@ test_http_push_nonff() {
 	'
 
 	test_expect_success 'non-fast-forward push shows help message' '
-		test_i18ngrep "To prevent you from losing history, non-fast-forward updates were rejected" output
+		test_i18ngrep "Updates were rejected because" output
 	'
 }

t/t5541-http-push.sh

@@ -167,7 +167,7 @@ test_expect_success 'push fails for non-fast-forward refs unmatched by remote he
 '
 
 test_expect_success 'push fails for non-fast-forward refs unmatched by remote helper: our output' '
-	test_i18ngrep "To prevent you from losing history, non-fast-forward updates were rejected" \
+	test_i18ngrep "Updates were rejected because" \
 		output
 '