comment out video derivative that makes webm (#500)

Author: cziaarm

config/initializers/file_set_derivatives_overrides.rb

@@ -51,8 +51,8 @@ def create_video_derivatives(filename)
     Hydra::Derivatives::VideoDerivatives.create(filename,
                                                 outputs: [{ label: :thumbnail, format: 'jpg',
                                                             url: derivative_url('thumbnail') },
-                                                          { label: 'webm', format: 'webm',
-                                                            url: derivative_url('webm') },
+#                                                          { label: 'webm', format: 'webm',
+#                                                            url: derivative_url('webm') },
                                                           { label: 'mp4', format: 'mp4',
                                                             url: derivative_url('mp4') }])
   end