fix compiler warning on CentOS builds.
fix compiler warning on CentOS builds.

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