Comment 3 for bug 987760

See bug #951161 - we support specifying a single IP address now, just don't specify /31 or /32

/32 and /31 are basically invalid network ranges:

 http://en.wikipedia.org/wiki/IPv4#Addresses_ending_in_0_or_255
 http://tools.ietf.org/html/rfc1122

 IP addresses are not permitted to have the value 0 or -1 for
 any of the <Host-number>, <Network-number>, or <Subnet-
 number> fields (except in the special cases listed above).
 This implies that each of these fields will be at least two
 bits long.