There is no string value assigned to the "ip.fragment.error",

There is no string value assigned to the "ip.fragment.error",
"ip.fragment", and "ip.fragments" fields, so make them FT_NONE, not
FT_STRING.  (Otherwise, if you try to do a "Match Selected" on them, we
dump core because the value is a null pointer and we try to dereference
it.)

git-svn-id: http://anonsvn.wireshark.org/wireshark/trunk@3512 f5534014-38df-0310-8fa8-9805f1628bb7