Fix for links and PPS

This change fixes:
- Interface value in the links to the "Firewall: Traffic Shaper" page;
- Read the proper PPS value from the qstats XML file. 

I don't know what I should do (or who I sould ask to) to recompile qstats after the change to  /pfsense-tools/pfPorts/qstats/files/qstats.c. This recompile is needed to nest the queues in the XML file. 

Thanks, 
Michele