title: MessageEmbed field values may not be empty
body: <p>everytime I am trying to do like: !help command , if the command doesn't have any aliases, it gives me that error in the console, I tried the following method which if there is no aliases for the specific command, it should return 'None' , here's the code:</p>
  <pre><code>            let command = helpArgs[0]
  
              if(helpArgs[0]){
              if(bot.commands.has(command)) {
                  command = bot.commands.get(command)
                  const embed = new Discord.MessageEmbed()
                  .setTitle(`${command.config.name}`)
                  .addField('Name', `${command.config.name}`)
                  .addField('Description', `${command.config.description}`)
                  .addField('Usage', `${command.config.usage}`)
                  .addField('Aliases', `${command.config.aliases !== undefined ? command.config.aliases : 'None'}`)
  message.channel.send(embed)
  </code></pre>
  <p>And here is the error:</p>
  <pre><code>7:14 GMT+0300 (Eastern European Summer Time)
  (node:11744) UnhandledPromiseRejectionWarning: RangeError [EMBED_FIELD_VALUE]: MessageEmbed field values may not be empty.
      at Function.normalizeField (C:\Users\\OneDrive\Documents\GitHub\Fergus\node_modules\discord.js\src\structures\MessageEmbed.js:425:23)
      at C:\Users\\OneDrive\Documents\GitHub\Fergus\node_modules\discord.js\src\structures\MessageEmbed.js:445:14
      at Array.map (&lt;anonymous&gt;)
      at Function.normalizeFields (C:\Users\\OneDrive\Documents\GitHub\Fergus\node_modules\discord.js\src\structures\MessageEmbed.js:444:8)
      at MessageEmbed.addFields (C:\Users\\OneDrive\Documents\GitHub\Fergus\node_modules\discord.js\src\structures\MessageEmbed.js:259:42) 
      at MessageEmbed.addField (C:\Users\\OneDrive\Documents\GitHub\Fergus\node_modules\discord.js\src\structures\MessageEmbed.js:250:17)  
      at Object.module.exports.run (C:\Users\\OneDrive\Documents\GitHub\Fergus\commands\Information\help.js:115:18)
      at processTicksAndRejections (internal/process/task_queues.js:97:5)
  (Use `node --trace-warnings ...` to show where the warning was created)
  (node:11744) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To terminate the node process on unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 1)
  (node:11744) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.
  </code></pre>
  <p>The error is at .addField('Aliases', <code>${command.config.aliases !== undefined ? command.config.aliases : 'None'}</code>) , I checked each field.</p>