fixed bug when potential fasta file is empty
fixed bug when potential fasta file is empty

deepakunni3/sequenceserver,lepbase/lepbase-sequenceserver,lepbase/lepbase-sequenceserver,elsiklab/sequenceserver,yeban/sequenceserver,IsmailM/sequenceserver,yeban/sequenceserver,lepbase/lepbase-sequenceserver,aldermossy/sequenceserver,vivekiitkgp/sequenceserver,elsiklab/sequenceserver,elsiklab/sequenceserver,deepakunni3/sequenceserver,deepakunni3/sequenceserver,aldermossy/sequenceserver,IsmailM/sequenceserver,jasminZ/sequenceserver,yeban/sequenceserver,vivekiitkgp/sequenceserver,aldermossy/sequenceserver,yeban/sequenceserver,IsmailM/sequenceserver,jasminZ/sequenceserver,aldermossy/sequenceserver,jasminZ/sequenceserver,vivekiitkgp/sequenceserver