Merge branch 'master' into glitch-soc/merge-upstream

Conflicts:
- `app/controllers/statuses_controller.rb`:
  Minor conflict due to theming system

app/models/media_attachment.rb

@@ -142,6 +142,7 @@ class MediaAttachment < ApplicationRecord
 
   validates :account, presence: true
   validates :description, length: { maximum: MAX_DESCRIPTION_LENGTH }, if: :local?
+  validates :file, presence: true, if: :local?
 
   scope :attached,   -> { where.not(status_id: nil).or(where.not(scheduled_status_id: nil)) }
   scope :unattached, -> { where(status_id: nil, scheduled_status_id: nil) }