bug993476: added comment explaining pidfile unlink checks
bug993476: added comment explaining pidfile unlink checks

rtsisyk/tarantool,vasilenkomike/tarantool,rtsisyk/tarantool,KlonD90/tarantool,ocelot-inc/tarantool,condor-the-bird/tarantool,mejedi/tarantool,condor-the-bird/tarantool,vasilenkomike/tarantool,guard163/tarantool,vasilenkomike/tarantool,condor-the-bird/tarantool,ocelot-inc/tarantool,nvoron23/tarantool,Sannis/tarantool,Sannis/tarantool,mejedi/tarantool,nvoron23/tarantool,dkorolev/tarantool,guard163/tarantool,vasilenkomike/tarantool,condor-the-bird/tarantool,guard163/tarantool,KlonD90/tarantool,nvoron23/tarantool,mejedi/tarantool,guard163/tarantool,Sannis/tarantool,dkorolev/tarantool,ocelot-inc/tarantool,guard163/tarantool,vasilenkomike/tarantool,rtsisyk/tarantool,KlonD90/tarantool,rtsisyk/tarantool,mejedi/tarantool,dkorolev/tarantool,condor-the-bird/tarantool,nvoron23/tarantool,KlonD90/tarantool,Sannis/tarantool,KlonD90/tarantool,ocelot-inc/tarantool,dkorolev/tarantool,nvoron23/tarantool,dkorolev/tarantool,Sannis/tarantool,nvoron23/tarantool