[core] better diagnostic in case of missing snapshot
[core] better diagnostic in case of missing snapshot

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