Better lsof to find process

Summary:
The previous recommendation doesn't always holds true. There are reported cases in which a process is listening to the specified port yet is not being listed by the lsof command as advised.

The command below seems to work better.

    sudo lsof -i :52342

Reviewed By: antonk52

Differential Revision: D47989269

fbshipit-source-id: ea216de00ef6edc90de58e9d3fe3a0579a171fea

desktop/flipper-ui-core/src/chrome/SettingsSheet.tsx

@@ -433,7 +433,7 @@ class SettingsSheet extends Component<Props, State> {
                       </span>
                       <br />
                       <code>
-                        sudo lsof -i -P | grep LISTEN | grep <b>52342</b>
+                        sudo lsof -i :52342
                         <br />
                         sudo kill &lt;PID&gt;
                       </code>