Add unique index to meta_data table.
Add unique index to meta_data table.

btrask/stronglink,iOSCowboy/stronglink,Ryezhang/stronglink,shaunstanislaus/stronglink,iOSCowboy/stronglink,feld/stronglink,btrask/stronglink,nkatsaros/stronglink,guiquanz/stronglink,Ryezhang/stronglink,iOSCowboy/stronglink,rmoorman/stronglink,yamingd/stronglink,btrask/stronglink,feld/stronglink,Lacra17/stronglink,Lacra17/stronglink,feld/stronglink,Ryezhang/stronglink,guiquanz/stronglink,nkatsaros/stronglink,btrask/stronglink,rmoorman/stronglink,rmoorman/stronglink,yamingd/stronglink,nkatsaros/stronglink,guiquanz/stronglink,shaunstanislaus/stronglink,yamingd/stronglink,shaunstanislaus/stronglink,Lacra17/stronglink