Fix #662. Update man page

Author: phaag

man/nfdump.1

@@ -848,11 +848,9 @@ True if the record ident field matches
 .Ar string.
 This filter can be used to filter out different sources.
 .Pp
-.It Cm inet
 .It Cm ipv4
 True if source and destination IP of a record are IPv4 IPs.
 .Pp
-.It Cm inet6
 .It Cm ipv6
 True if source and destination IP of a record are IPv6 IPs.
 .Pp