[BUG] Monitor downloads

[bengarrett]

Include a notice or alert recommending a browser restart when toggling the Monitor downloads while granting permission.

Otherwise the following error may occur.

Last error for %s Reason: %s monitor downloads send message 
A listener indicated an asynchronous response by returning true, 
but the message channel closed before a response was received

Trigger

  listen() {
    // checkbox toggles
    const toggles = () => {
      const value = document.getElementById(`${this.elementId}`).checked
      let monitor = false // for downloadViewer
      // special cases that have permission dependencies
      switch (this.elementId) {
        case `downloadViewer`:
          Console(`toggled downloadViewer: ${value}`)
          if (value === true) monitor = true
          chrome.runtime.sendMessage({ monitorDownloads: monitor }, () => {
            if (CheckLastError(`monitor downloads send message`)) return // TRIGGER
          })
          break
      }
    }

[bengarrett]

Complete.