vinyl: don't create empty run on split
vinyl: don't create empty run on split

All keys before the split key can cancel each other, in which case the
new run is going to be empty. We are not ready to handle empty runs, so
we should silently cancel range file creation in this case.

rtsisyk/tarantool,rtsisyk/tarantool,rtsisyk/tarantool,mejedi/tarantool,mejedi/tarantool,rtsisyk/tarantool,mejedi/tarantool,mejedi/tarantool