revert unexpected change to ble advertising interval on nrf52

Author: liamcottle

src/helpers/nrf52/SerialBLEInterface.cpp

@@ -86,7 +86,7 @@ void SerialBLEInterface::startAdv() {
    * https://developer.apple.com/library/content/qa/qa1931/_index.html   
    */
   Bluefruit.Advertising.restartOnDisconnect(false); // don't restart automatically as we handle it in onDisconnect
-  Bluefruit.Advertising.setInterval(32, 1600);
+  Bluefruit.Advertising.setInterval(32, 244);
   Bluefruit.Advertising.setFastTimeout(30);      // number of seconds in fast mode
   Bluefruit.Advertising.start(0);                // 0 = Don't stop advertising after n seconds