[Debug] fix nanos in log timestamp

The timestamp consists of <hour><minutes>.<nanos> but the calculation of
the nanos in the current minute was broken.
A minute are 60 * 10^9 nanoseconds and not 10^9.

emper/Debug.cpp

@@ -33,7 +33,7 @@ void emper_add_timestamp_to(std::ostringstream& logMessage) {
 	auto time_since_epoch = now_nanos.time_since_epoch();
 	long time_since_epoch_long = time_since_epoch.count();
 
-	long remaining_nanos = time_since_epoch_long % 1000000000;
+	long remaining_nanos = time_since_epoch_long % 60000000000;
 	logMessage << remaining_nanos;
 }