check for receipt address before calling back

lib/contracts/blockchain.js

@@ -245,15 +245,18 @@ class Blockchain {
     let hash;
     let calledBacked = false;
 
-    function callback() {
+    function callback(err, receipt) {
       if (calledBacked) {
         return;
       }
+      if (!err && !receipt.contractAddress) {
+        return; // Not deployed yet. Need to wait
+      }
       if (interval) {
         clearInterval(interval);
       }
       calledBacked = true;
-      cb(...arguments);
+      cb(err, receipt);
     }
 
     // This interval is there to compensate for the event that sometimes doesn't get triggered when using WebSocket