Updated precompiled contracts test

StateTests/stExample.json

@@ -37,14 +37,14 @@
             "095e7baea6a6c7c4c2dfeb977efac326af552d87" : {
                 "balance" : "1000000000000000000",
                 "code" : "0x6001600101600055",
-                "nonce" : 0,
+                "nonce" : "0",
                 "storage" : {
                 }
             },
             "a94f5374fce5edbc8e2a8697c15331677e6ebf0b" : {
                 "balance" : "1000000000000000000",
-                "code" : "",
-                "nonce" : 0,
+                "code" : "0x",
+                "nonce" : "0",
                 "storage" : {
                 }
             }