Removes check for conflicts from NetworkDisconnect

This removes the check for conflicts from the Haskell
version of the OpCode NetworkDisconnect. This alignes
the Haskell code with the patch
"Force conflicts check in LUNetworkDisconnect" (which
is currently under review). I will submit these patches
together then.

This is a cherry-pick of commit 0ae4b355.

Signed-off-by: Helga Velroyen <helgav@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>
Reviewed-by: Michele Tartara <mtartara@google.com>