OZG-3074 fix E2E: adjust create postfach mail button

goofy-client/apps/goofy-e2e/src/integration/main-tests/postfach-mail/postfach-mail-error.e2e-spec.ts

@@ -82,7 +82,7 @@ describe('PostfachMail error', () => {
 		})
 
 		it('should show postfach mail button', () => {
-			exist(postfachMailContainer.getButton());
+			exist(postfachMailContainer.getCreateButtonWithText());
 		})
 
 		it('should show postfach mail button in subnavigation', () => {