netty consumer using UDP should release the datagram channel factory

There is a bug reported in CAMEL-6856 we need to backport to our patch branches

To ssh://git@forge.fusesource.com/camel.git
79275c1..05f3446 2.10.0.fuse-7-1-x-patch -> 2.10.0.fuse-7-1-x-patch
0daa9fc..4dc1e0c 2.10.0.fuse-7-1-x-stable -> 2.10.0.fuse-7-1-x-stable
cb637ef..60bea29 2.10.0.fuse-7-2-x-patch -> 2.10.0.fuse-7-2-x-patch
1b51870..4bf6f18 2.10.0.fuse-7-2-x-stable -> 2.10.0.fuse-7-2-x-stable
bb393e0..d8d6e86 2.10.x-fuse -> 2.10.x-fuse
0009fde..2fb48f3 2.9.0.fuse-7-0-x-patch -> 2.9.0.fuse-7-0-x-patch
50519d2..5940a46 2.9.0.fuse-7-0-x-stable -> 2.9.0.fuse-7-0-x-stable