-Removes the unique constraint on the 'addr' field from the masternode collection
NOTE: If you are experiencing a mongo duplicate key error while running a masternode sync, the easiest way to correct the problem is as follows:
1) #Stop the explorer
2) git pull
3) mongo
4) use explorerdb
5) db.masternodes.drop()
6) exit
7) #Restart the explorer
8) /path/to/explorer/scripts/sync.sh /path/to/node masternodes
joeuhren
3df1449292