[FAB-6512] Change gossip leader election default

The sampleconfig/core.yaml file defaults to disabling leader election
and instead setting the peer to be a leader.

This is the wrong default, because enabling leader election fixes a
number of potential errors, including peers permanently disconnectoin
from the ordering service during a network partition, and allows a peer
to join a channel with a genesis block which does not contain the peer's
org definition.

Change-Id: I1f6de1d5e7a0275003450756e6303e70643a04ca
Signed-off-by: Jason Yellick <jyellick@us.ibm.com>

Author: Jason Yellick

sampleconfig/core.yaml

@@ -113,12 +113,12 @@ peer:
         # connection with ordering service and use delivery protocol
         # to pull ledger blocks from ordering service. It is recommended to
         # use leader election for large networks of peers.
-        useLeaderElection: false
+        useLeaderElection: true
         # Statically defines peer to be an organization "leader",
         # where this means that current peer will maintain connection
         # with ordering service and disseminate block across peers in
         # its own organization
-        orgLeader: true
+        orgLeader: false
 
         # Overrides the endpoint that the peer publishes to peers
         # in its organization. For peers in foreign organizations