message: Remove unneeded padding in chat.
diff: justify-content: center
  align-items: flex-start
  z-index: $zindex-chat-window
  - padding-right: ($grid-gutter-width / 2)
  - padding-left: ($grid-gutter-width / 2)
  @media $media-sm-up
  top: $shell-top-nav-height + 10px
  