All translated ICMPv6 packets that exceed the minimal IPv6 MTU get
truncated but according to RFC 4443 2.4 only ICMPv6 error messages
(type < 128) need to be truncated.
With this commit, truncate only ICMPv6 error messages.
Type: fix
Change-Id: Ic455352de2ff4ff6aa3421b46a2a54923f2d3f80 Signed-off-by: Alexander Chernavin <achernavin@netgate.com>