Remove bottom margin for flash message on home page

Flash Messages

Remove margin-bottom: 16px from .no-ssh-key-message and .project-limit-message. This added an unnecessary margin between the notification and the content which was brought up in this issue #14797 (closed).

Affected files:

./app/assets/javascripts/project.js.coffee:      $(@).parents('.no-ssh-key-message').remove()
./app/assets/stylesheets/pages/projects.scss:.no-ssh-key-message, .project-limit-message {
./app/views/shared/_no_ssh.html.haml:  .no-ssh-key-message.alert.alert-warning.hidden-xs
./app/assets/javascripts/user.js.coffee:    $('.hide-project-limit-message').on 'click', (e) ->
./app/assets/javascripts/user.js.coffee:      $(@).parents('.project-limit-message').remove()
./app/assets/stylesheets/pages/projects.scss:.no-ssh-key-message, .project-limit-message {
./app/views/shared/_project_limit.html.haml:  .project-limit-message.alert.alert-warning.hidden-xs
./app/views/shared/_project_limit.html.haml:      = link_to 'Remind later', '#', class: 'hide-project-limit-message alert-link'

Screenshots:

Before:

After: