* master:
  Fix migration without DOWNTIME clause specified
  Fix CSS classes
  fix missing @ symbol
  Update CHANGELOG.md for 8.16.7
  Update CHANGELOG.md for 8.16.7
  Update CHANGELOG.md for 8.16.7
  Make RuboCop happy
  Add development fixtures for nested groups
  Align last column buttons with new environment button
  Removed jQuery UI draggable
  ensure webpack dev server proxy connects regardless of request headers
  Keep consistent in handling indexOf results
  Replace setInterval with setTimeout to prevent highly frequent requests
  Add feature specs for three types of user uploads
  Minor refactoring of Uploaders
  Fix #27840 - Improve the search bar experience on mobile
  Fix false positive caused by non-interpolated string use
  Fix inline comment images by removing wrapper #20890