Implement token bucket duty cycle enforcement

examples/simple_repeater/MyMesh.cpp

@@ -689,7 +689,7 @@ MyMesh::MyMesh(mesh::MainBoard &board, mesh::Radio &radio, mesh::MillisecondCloc
 
   // defaults
   memset(&_prefs, 0, sizeof(_prefs));
-  _prefs.airtime_factor = 1.0;   // one half
+  _prefs.airtime_factor = 1.0;
   _prefs.rx_delay_base = 0.0f;   // turn off by default, was 10.0;
   _prefs.tx_delay_factor = 0.5f; // was 0.25f
   _prefs.direct_tx_delay_factor = 0.2f; // was zero