title: Symfony 4 SQLSTATE[42000] Specified key was too long
body: <p>I am trying to create database from Entity in Symfony 4. However the result is:</p>
  
  <pre><code>SQLSTATE[42000]: Syntax error or access violation: 1071 Specified key was too long; max key length is 767 bytes
  </code></pre>
  
  <p>I know this is because it is trying to use utf8mb4 charset and utf8mb4_unicode_ci collation. I've tried to replace my doctrine.yaml file to utf8 and utf8_unicode_ci as well as:</p>
  
  <pre><code>@ORM\Table(name="users", options={"collate"="utf8_unicode_ci", "charset"="utf8", "engine"="MyISAM"})
  </code></pre>
  
  <p>But it's still trying to use utf88mb4. How can I force it to use utf8?</p>