Bad configs will cause channel config components to
return nil channelconfig. This can happen with
handcrafted configs using configtxlator tool.

This is really a side effect of not catching an earlier
error. Fixing the root cause.

Change-Id: I01828d8e2c1520a3c694c49587e5aca3867681d3
Signed-off-by: Srinivasan Muralidharan <srinivasan.muralidharan99@gmail.com>