message: center dialog title
diff: @@ -14,7 +14,10 @@ See the License for the specific language governing permissions and
  limitations under the License.
  */
  -.mx_MessageEditHistoryDialog ul {
  +.mx_MessageEditHistoryDialog .mx_Dialog_header > .mx_Dialog_title {
  + text-align: center;
  +}
  +
  .mx_MessageEditHistoryDialog {
  display: flex;
  flex-direction: column;
  