Fix Entry node missing problem happening in PjOrion v2 sample

[FXTi]

Error info:

INFO:simplifier:43 basic blocks eliminated
Traceback (most recent call last):
  File "./main.py", line 72, in <module>
    process(args.ifile, args.ofile)
  File "./main.py", line 58, in process
    deob = parse_code_object(rootCodeObject)
  File "./main.py", line 20, in parse_code_object
    co_codestring = deobfuscate(codeObject.co_code)
  File "/tmp/sim/deobfuscator.py", line 75, in deobfuscate
    render_graph(simplifier.bb_graph, 'after_forwarder.svg')
  File "/tmp/sim/utils/rendergraph.py", line 34, in render_graph
    entryblock = nx.get_node_attributes(bb_graph, 'isEntry').keys()[0]
IndexError: list index out of range

It happened when the node labeled isEntry is merged with other node, without passing its isEntry attribute. So there's no available isEntry node left after first forward elimination.

This is sample pyc file for you to test. : ) py.zip