Error flash appears unexpectedly when cancel captcha before sending SMS

Summary

Error flash appears unexpectedly when user cancel captcha before sending SMS

Steps to reproduce

1. enter https://jihulab.com/users/sign_up
2. fill the phone input with an available phone number
3. click get code button
4. click the close button on the top right corner of the captcha.

Example Project

What is the current bug behavior?

Error flash appears unexpectedly

What is the expected correct behavior?

Error flash should not appear

Relevant logs and/or screenshots

Output of checks

Results of GitLab environment info

Expand for output related to GitLab environment info

(For installations with omnibus-gitlab package run and paste the output of:
`sudo gitlab-rake gitlab:env:info`)

(For installations from source run and paste the output of:
`sudo -u git -H bundle exec rake gitlab:env:info RAILS_ENV=production`)

Results of GitLab application Check

Expand for output related to the GitLab application check

(For installations with omnibus-gitlab package run and paste the output of:
sudo gitlab-rake gitlab:check SANITIZE=true)
(For installations from source run and paste the output of:
sudo -u git -H bundle exec rake gitlab:check RAILS_ENV=production SANITIZE=true)
(we will only investigate if the tests are passing)

Possible fixes