Do not generate empty lemmas in guesser.
Do not generate empty lemmas in guesser.

Currently guesser could return an empty lemma (e.g., for word "ama").

ufal/morphodita,ufal/morphodita,ufal/morphodita,ufal/morphodita,ufal/morphodita,ufal/morphodita,ufal/morphodita,ufal/morphodita