...and also a leading ','... (oops 2)

See #2408

Author: cmaglie

arduino/avr/cores/arduino/WInterrupts.c

@@ -62,7 +62,7 @@ static volatile voidFuncPtr intFunc[EXTERNAL_NUM_INTERRUPTS] = {
     nothing,
 #endif
 #if EXTERNAL_NUM_INTERRUPTS > 0
-    nothing
+    nothing,
 #endif
 };
 // volatile static voidFuncPtr twiIntFunc;