Wait for catchup when starting the miner

utils/cmd.go

@@ -204,6 +204,10 @@ func StartMining(ethereum *eth.Ethereum) bool {
 			miner = ethminer.NewDefaultMiner(addr, ethereum)
 			// Give it some time to connect with peers
 			time.Sleep(3 * time.Second)
+			for !ethereum.IsUpToDate() == false {
+				time.Sleep(5 * time.Second)
+			}
+
 			logger.Infoln("Miner started")
 			miner := ethminer.NewDefaultMiner(addr, ethereum)
 			miner.Start()