fix count when testing composite error output

[minrk]

fixes this failure

[takluyver]

Just tested this, and there's a separate test failure on Python 3 that I hadn't spotted before (sorry):

======================================================================
ERROR: Truncate CompositeErrors with many exceptions
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Traceback (most recent call last):
  File "/home/thomas/.ipy_pr_tests/venv-python3.2/lib/python3.2/site-packages/ip
ython-1.0.dev-py3.2.egg/IPython/parallel/tests/test_view.py", line 644, in test_
compositeerror_truncate
    lines = e.render_traceback()
UnboundLocalError: local variable 'e' referenced before assignment

It's this block - when you use except Exception as e:, e is now only in scope for the exception handler, to avoid a reference cycle. It's easy to work around - just assign it to another variable within the except block.