Remove incorrect execution of OP_0. That code was never reached, because OP_0 is not an opcode in terms of chunk.isOpCode()). However, it lead to believe that OP_0 pushes the vector [0], rather than correctly the empty vector to the stack.

Because the code was never executed, this bug could never trigger a test. Afaict, script.cpp does not have the corresponding case in its switch block.

core/src/main/java/com/google/bitcoin/script/Script.java

@@ -660,10 +660,7 @@ public class Script {
                     continue;
                 
                 switch(opcode) {
-                case OP_0:
-                    // This is also OP_FALSE (they are both zero).
-                    stack.add(new byte[]{0});
-                    break;
+                // OP_0 is no opcode
                 case OP_1NEGATE:
                     stack.add(Utils.reverseBytes(Utils.encodeMPI(BigInteger.ONE.negate(), false)));
                     break;