Currently peer panics and dies while receiving genesis of the ordering
service, there is no way to recover after such a failure (even after
restarting the peer). This commit takes care to check block type before
trying to create a channel.

Change-Id: Ia72c3e6cccff0632b81f1334fb87841a2aecdab9
Signed-off-by: Artem Barger <bartem@il.ibm.com>