message: improving video settings
diff: <hr/>
  <p class="title" i18n>Video transcoding:</p>
  - <div class="form-group row">
  + <div class="form-group row" [hidden]="simplifiedMode">
  <label class="col-md-2 control-label" for="format" i18n>Format</label>
  <div class="col-md-10">
  <select id="format" class="form-control" [(ngModel)]="settings.server.transcoding.format"
  </div>
  </div>
  - <div class="form-group row">
  + <div class="form-group row" [hidden]="simplifiedMode">
  <label class="col-md-2 control-label" for="codec" i18n>Codec</label>
  <div class="col-md-10">
  <select id="codec" class="form-control" [(ngModel)]="settings.server.transcoding.codec"
  </div>
  </div>
  - <div class="form-group row">
  + <div class="form-group row" [hidden]="simplifiedMode">
  <label class="col-md-2 control-label" for="fps" i18n>FPS</label>
  <div class="col-md-10">
  <select id="fps" class="form-control" [(ngModel)]="settings.server.transcoding.fps"
  