Fix KeyError in Vectors.most_similar. Fixes #2648
Fix KeyError in Vectors.most_similar. Fixes #2648

explosion/spaCy,honnibal/spaCy,explosion/spaCy,honnibal/spaCy,spacy-io/spaCy,spacy-io/spaCy,honnibal/spaCy,explosion/spaCy,spacy-io/spaCy,spacy-io/spaCy,spacy-io/spaCy,honnibal/spaCy,spacy-io/spaCy,explosion/spaCy,explosion/spaCy,explosion/spaCy