Avoid missing Queue.Empty reference at process termination
Avoid missing Queue.Empty reference at process termination

Fixes #88
gBritz/dpxdt,Medium/dpxdt,mabushadi/dpxdt,bslatkin/dpxdt,mabushadi/dpxdt,gBritz/dpxdt,weeksghost/dpxdt,weeksghost/dpxdt,Medium/dpxdt,ygravrand/dpxdt,bslatkin/dpxdt,weeksghost/dpxdt,gBritz/dpxdt,Medium/dpxdt,Medium/dpxdt,mabushadi/dpxdt,steven-hadfield/dpxdt,mabushadi/dpxdt,bslatkin/dpxdt,bslatkin/dpxdt,ygravrand/dpxdt,steven-hadfield/dpxdt,ygravrand/dpxdt,weeksghost/dpxdt,gBritz/dpxdt,ygravrand/dpxdt,steven-hadfield/dpxdt,steven-hadfield/dpxdt