[VIM] FortiGate issue - "EPSV" not "ESPV"

[Steven M. Christey]

Various vuln DBs have used the acronym "ESPV" for a recent FortiGate
FTP Anti-Virus issue:

  http://www.fortinet.com/FortiGuardCenter/advisory/FG-2006-15.html

However the proper acronym is "EPSV" for Extended Passive Mode, as
defined in RFC2428:

  http://www.networksorcery.com/enp/rfc/rfc2428.txt

- Steve