[FAB-1650] Rename chain-config.proto

https://jira.hyperledger.org/browse/FAB-1650

The chain-config.proto file is misleadingly named, as it contains only
MSP principal things.  The hyphen in the name is also causing problems
with the proto generation for the python bdd, so this should be changed.

Change-Id: Ieb0165826c38ad995cda1cdb351fdc987625d642
Signed-off-by: Jason Yellick <[email protected]>

Author: Jason Yellick