Revert last commit, if defined... delay

Delay is necessary for faster devices in some cases
- reduced delay by 30us for testing further

RF24.cpp

@@ -735,7 +735,9 @@ void RF24::startListening(void)
   }
 
   // Go!
-  //delayMicroseconds(130);
+  #if defined (RF24_LINUX) || defined (__arm__)
+    delayMicroseconds(100);
+  #endif
   listeningStarted = 1;
 }