Perform unzip quietly in UpdatePagesService

Closes https://gitlab.com/gitlab-org/gitlab-ee/issues/225

app/services/projects/update_pages_service.rb

@@ -93,10 +93,11 @@ module Projects
       end
       # Requires UnZip at least 6.00 Info-ZIP.
+      # -qq be (very) quiet
       # -n  never overwrite existing files
       # We add * to end of SITE_PATH, because we want to extract SITE_PATH and all subdirectories
       site_path = File.join(SITE_PATH, '*')
-      unless system(*%W(unzip -n #{artifacts} #{site_path} -d #{temp_path}))
+      unless system(*%W(unzip -qq -n #{artifacts} #{site_path} -d #{temp_path}))
         raise 'pages failed to extract'
       end
     end