Show import notice in callout block

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

app/views/projects/new.html.haml

@@ -47,7 +47,7 @@
               %span Import existing repo
             .col-sm-10
               = f.text_field :import_url, class: 'form-control', placeholder: 'https://github.com/randx/six.git'
-              %p.help-block
+              .bs-callout.bs-callout-info
                 This url must be publicly accessible or you can add a username and password like this: https://username:password@gitlab.com/company/project.git.
                 %br
                 Import timeout is 2 minutes. For big repositories use clone/push combination.