message: multimedia-explanation: show type change only if there is actually a choice
diff: @@ -127,10 +127,12 @@ export function MultimediaExplanationEditor(props: MultimediaExplanationProps) {
  </option>
  </select>
  </div>
  + {props.config.plugins.length > 1 ? (
  <div>
  <strong>{props.config.i18n.changeMultimediaType}</strong>
  {PluginSelection}
  </div>
  + ) : null}
  </React.Fragment>
  )
  @@ -146,6 +148,7 @@ export function MultimediaExplanationEditor(props: MultimediaExplanationProps) {
  setShowOptions(false)
  }}
  >
  + {props.config.plugins.length > 1 ? (
  <PluginToolbarButton
  icon={<Icon icon={faRandom} />}
  label={props.config.i18n.changeMultimediaType}
  @@ -153,6 +156,7 @@ export function MultimediaExplanationEditor(props: MultimediaExplanationProps) {
  setShowOptions(true)
  }}
  />
  + ) : null}
  {showOptions ? (
  <InlineOptions>
  {props.config.plugins
  