activeprocess.d: fix unknown active process issue
activeprocess.d: fix unknown active process issue

sometimes, after running for a while, active process name doesn't change and new terminal shows unknown active process. this commit fixes this problem.
gnunn1/tilix,gnunn1/terminix,dsboger/tilix,gnunn1/terminix,gnunn1/tilix,dsboger/tilix,gnunn1/tilix