Fix typo

Author: khoih-prog

examples/ESP32/RPM_Measure/RPM_Measure.ino

@@ -103,7 +103,7 @@ void IRAM_ATTR TimerHandler0()
 
 #if (TIMER_INTERRUPT_DEBUG > 0)
       Serial.print("RPM = "); Serial.print(avgRPM);
-      Serial.print(", rotationTime ms = "); Serial.println(rotationTime * TIMER1_INTERVAL_MS);
+      Serial.print(", rotationTime ms = "); Serial.println(rotationTime * TIMER0_INTERVAL_MS);
 #endif
 
     rotationTime = 0;