message: make end-to-end test failure more verbose
diff: @@ -61,7 +61,7 @@ module.exports = async function signup(session, username, password, homeserver)
  await session.query(".mx_Field_valid #mx_RegistrationForm_password");
  //check no errors
  const errorText = await session.tryGetInnertext('.mx_Login_error');
  - assert.strictEqual(!!errorText, false);
  + assert.strictEqual(errorText, null);
  //submit form
  //await page.screenshot({path: "beforesubmit.png", fullPage: true});
  await registerButton.click();
  