message: Add a missing change for `FontAtlasImpl`
diff: @@ -8,6 +8,8 @@ import { FontAtlas } from "./FontAtlas";
  import { Logger, getLogger, log } from "extraterm-logging";
  +const TWO_TO_THE_24 = 2 ** 24;
  +
  export class FontAtlasImpl implements FontAtlas {
  private _log: Logger = null;
  private _pages: FontAtlasPage[] = [];
  