download_mitochrondrion_ncbi.sh: some incomplete records (server MARBEC)

• the two separating lines between some records are missing \\ + [empty line]

    16561 atcacgatg
//

LOCUS       MW172448               16569 bp    DNA     circular PRI 09-DEC-2020

• some records are incompletes (ex: MW172448)
• some sequences are cut (ex: NC_057214, MN531849)