fix cpm calculation.\nNote: while calculation is correct now the wrong method is used to determine cpm. a fixed time interval should be used.

radangeld/main.cpp

 			if (validevents > 0)
 			{
 				cpm << timestamp
-				    << static_cast<double> (validevents / (timestamp - oldtimestamp) * 1000 * 60);
+				    << static_cast<double> (validevents / ((timestamp - oldtimestamp) / 1000.0 / 1000.0 ) * 60.0);
 
 				cpmsocket.send (cpm);