Inconsistency with API on empty strings

[nkkarpov]

For example, edlib.align("ACGT", "", k=1) returns 4 instead of -1. Additionally, it appears that the CIGAR string and locations are unreliable when the query string is empty, as they contain None even when k is larger than the edit distance.

edlib.align("ACGT", "", k=5, task="path")
{'editDistance': 4,
 'alphabetLength': 4,
 'locations': [(None, -1)],
 'cigar': None}