Add fix for emptyTransaction test

ethereumj-core/src/main/java/org/ethereum/core/TransactionExecutor.java

@@ -89,6 +89,16 @@ public class TransactionExecutor {
             return;
         }
 
+        //Insert gas cost protection
+        BigInteger gasLimit = new BigInteger(1, tx.getGasLimit());
+        if (gasLimit.compareTo(BigInteger.ZERO) == 0) {
+            logger.debug("No gas limit set on transaction: hash={}",
+                    Hex.toHexString(tx.getHash()));
+
+            receipt.setCumulativeGas(0);
+            this.receipt = receipt;
+            return;
+        }
 
         // FIND OUT THE TRANSACTION TYPE
         final byte[] receiverAddress;

ethereumj-core/src/test/java/test/ethereum/jsontestsuite/GitHubStateTest.java

@@ -110,12 +110,10 @@ public class GitHubStateTest {
         GitHubJSONTestSuite.runGitHubJsonStateTest(json, excluded);
     }
 
-
     @Test // todo: fix: excluded test
     public void stTransactionTest() throws ParseException {
 
         Set<String> excluded = new HashSet<>();
-        excluded.add("EmptyTransaction");
         //todo:    it goes OOG, because no gasLimit is given. So it does not change the state.