Fix emojii autocomplete

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

app/views/layouts/_init_auto_complete.html.haml

 :javascript
   GitLab.GfmAutoComplete.dataSource = "#{autocomplete_sources_project_path(@project)}"
-  GitLab.GfmAutoComplete.Emoji.assetBase = '#{image_path("emoji")}'
+  GitLab.GfmAutoComplete.Emoji.assetBase = '/assets/emoji'
   GitLab.GfmAutoComplete.setup();