FIX: Unable to connect on Debian testing

I only was able to connect with printrun after connect/disconnect using Repetier or Arduino.

After a successfull connection with Printrun, if I disconnect i was unable to connect again. This trick allows to connect and disconnect from Printrun without problems.

I'm using:
Debian testing
Linux acer 3.14-2-686-pae #1 SMP Debian 3.14.15-2 (2014-08-09) i686 GNU/Linux
Python 2.7.8
pyserial 2.6