Merge pull request #1692 from letolabs/FSM

Fix os x build

src/cc/gateways.cpp

@@ -1114,6 +1114,7 @@ std::string GatewaysClaim(uint64_t txfee,uint256 bindtxid,std::string refcoin,ui
         if ( CCchange != 0 ) mtx.vout.push_back(MakeTokensCC1vout(EVAL_GATEWAYS,CCchange,gatewayspk));     
         return(FinalizeCCTx(0,cp,mtx,mypk,txfee,EncodeGatewaysClaimOpRet('C',tokenid,bindtxid,refcoin,deposittxid,destpub,amount)));
     }
+    return("");
 }
 
 std::string GatewaysWithdraw(uint64_t txfee,uint256 bindtxid,std::string refcoin,CPubKey withdrawpub,int64_t amount)