Squash -Wunused-parameter warning

Author: eric-wieser

src/avr/Servo.cpp

@@ -202,7 +202,8 @@ static void finISR(timer16_Sequence_t timer)
     timerDetach(TIMER3OUTCOMPAREA_INT);
   }
 #else
-    //For arduino - in future: call here to a currently undefined function to reset the timer
+  //For arduino - in future: call here to a currently undefined function to reset the timer
+  (void) timer;  // squash "unused parameter 'timer' [-Wunused-parameter]" warning
 #endif
 }