title: Material-UI : How to properly set userAgent for server-side rendering
body: <p>I'm getting this warning : </p>
  
  <pre><code>    Material-UI: userAgent should be supplied in the muiTheme 
      context for server-side rendering
  </code></pre>
  
  <p>with the following server side rendering setup, what am I doing wrong :</p>
  
  <pre><code>    match({routes: R(), location}, (error, redirectLocation, renderProps) =&gt; {
      if (error) {
          console.error("error: "+ error)
      } else if (redirectLocation) {
          console.error("redirect to " + redirectLocation)
      } else if (renderProps) {
  
          const theme = getMuiTheme({userAgent: "all"})
  
          page = ReactDOMServer.renderToStaticMarkup(
          &lt;MuiThemeProvider muiTheme={theme}&gt;
              &lt;Provider store={store}&gt;
                  &lt;RouterContext {...renderProps} /&gt;
              &lt;/Provider&gt;
          &lt;/MuiThemeProvider&gt;
          )
      } else {
          console.error("location nof found: '"+ location +"'")
      }
      })
  </code></pre>