message: emails - supported color theme
diff: <mj-all font-family="Roboto, Helvetica, sans-serif"></mj-all>
  <mj-text font-weight="300" color="#616161" line-height="20px"></mj-text>
  </mj-attributes>
  + <mj-raw>
  + <meta name="color-scheme" content="light">
  + <meta name="supported-color-schemes" content="light">
  + </mj-raw>
  </mj-head>
  