Fix issue error message layout

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

app/views/projects/issues/_form.html.haml

@@ -3,11 +3,15 @@
   %hr
   - if @repository.exists? && !@repository.empty? && @repository.contribution_guide && !@issue.persisted?
     - contribution_guide_url = project_blob_path(@project, tree_join(@repository.root_ref, @repository.contribution_guide.name))
-    .alert.alert-info.col-sm-10.col-sm-offset-2
-      ="Please review the <strong>#{link_to "guidelines for contribution", contribution_guide_url}</strong> to this repository.".html_safe
+    .row
+      .col-sm-10.col-sm-offset-2
+        .alert.alert-info
+          = "Please review the <strong>#{link_to "guidelines for contribution", contribution_guide_url}</strong> to this repository.".html_safe
 
   = form_for [@project, @issue], html: { class: 'form-horizontal issue-form' } do |f|
     -if @issue.errors.any?
+      .row
+        .col-sm-10.col-sm-offset-2
           .alert.alert-danger
             - @issue.errors.full_messages.each do |msg|
               %span= msg