write an additional newline when exiting shell after EOF
write an additional newline when exiting shell after EOF

If the user inputs Ctrl-D to exit the SensorBee shell, then
the next terminal input prompt was written right after the SensorBee
shell input prompt, which would a) be not pretty and b) might break
command editing in the terminal. Therefore we write one more line
break if the SensorBee shell exits after EOF.

sensorbee/sensorbee,sensorbee/sensorbee