Split merge conflict messages on 2 lines

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

app/views/projects/merge_requests/widget/open/_conflicts.html.haml

 - if @merge_request.can_be_merged_by?(current_user)
   %h4
     This merge request contains merge conflicts that must be resolved.
-    You can try it manually on the
+  %p
+    You can merge it manually using the
     %strong
       = link_to "command line", "#modal_merge_info", class: "how_to_merge_link vlink", title: "How To Merge", "data-toggle" => "modal"
 - else