Move freebeat_serialport to the bottom of the settings property block

Keeps this branch's own setting addition last, after master's
waterrower_usb, matching the convention of appending new settings.

Author: cagnulein

src/settings.qml

@@ -1735,9 +1735,8 @@ import AndroidStatusBar 1.0
             property int mywhoosh_link_right_power: 0
             property int mywhoosh_link_camera_value: 1
             property int mywhoosh_link_emote_value: 1
-            property string freebeat_serialport: ""
-
             property bool waterrower_usb: false
+            property string freebeat_serialport: ""
         }