Fix a memory leak in list-tubes-watched.
Fix a memory leak in list-tubes-watched.

Closes gh-29.

aidaima/beanstalkd,r3jack/beanstalkd,justintung/beanstalkd,pinguo-xudianyang/beanstalkd,LomoX-Offical/beanstalkd-win,r3jack/beanstalkd,amyvmiwei/beanstalkd,justintung/beanstalkd,amyvmiwei/beanstalkd,potatosalad/beanstalkd,PhillipMwaniki/beanstalkd,yetone/beanstalkd,Qihoo360/beanstalkd-win,davies/beanstalkd,cgvarela/beanstalkd,wyzssw/beanstalkd,bmhatfield/beanstalkd,naderman/beanstalkd,diditaxi/beanstalkd,wyzssw/beanstalkd,tdg5/beanstalkd,qbdsoft/beanstalkd,handautsav/beanstalkd,aidaima/beanstalkd,davies/beanstalkd,diditaxi/beanstalkd,wfxiang08/beanstalkd,mobliyishengyuan/beanstalkd,bmhatfield/beanstalkd,kr/beanstalkd,lzpfmh/beanstalkd,kr/beanstalkd,PhillipMwaniki/beanstalkd,ifduyue/beanstalkd,cgvarela/beanstalkd,lzpfmh/beanstalkd,ifduyue/beanstalkd,pinguo-xudianyang/beanstalkd,CompendiumSoftware/beanstalkd,CompendiumSoftware/beanstalkd,JensRantil/beanstalkd,yetone/beanstalkd,mickeyouyou/beanstalkd,potatosalad/beanstalkd,tdg5/beanstalkd,handautsav/beanstalkd,qbdsoft/beanstalkd,orangeholic/beanstalkd,mobliyishengyuan/beanstalkd,orangeholic/beanstalkd,wfxiang08/beanstalkd,mickeyouyou/beanstalkd,naderman/beanstalkd,Qihoo360/beanstalkd-win,LomoX-Offical/beanstalkd-win,JensRantil/beanstalkd,naderman/beanstalkd