Disconnect on F1 boards when 'break' is received if connected. This

happens when the device reboots due to incorrect hardware
initialisation.  This prevents the GUI saying 'waiting for data'.

See https://github.com/cleanflight/cleanflight/pull/1436

Since the problem is already fixed in firmware there's not much reason
to spent development working on additional GUI fixes.  A disconnect will
suffice.

js/serial.js

@@ -68,6 +68,12 @@ var serial = {
                                 });
                             }
                             break;
+                        case 'break':
+                            // This occurs on F1 boards with old firmware.
+                            if (GUI.connected_to || GUI.connecting_to) {
+                                $('a.connect').click();
+                            }
+                            break;
                         case 'timeout':
                             // TODO
                             break;