update output file to reflect new test of exception object str-ness

Lib/test/output/test_exceptions

 test_exceptions
 5. Built-in exceptions
+spam
 AttributeError
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 EOFError
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 IOError
+spam
 ImportError
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 IndexError
+spam
 KeyError
+spam
 KeyboardInterrupt
 (not testable in a script)
+spam
 MemoryError
 (not safe to test)
+spam
 NameError
+spam
 OverflowError
+spam
 RuntimeError
 (not used any more?)
+spam
 SyntaxError
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 SystemError
 (hard to reproduce)
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 SystemExit
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 TypeError
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 ValueError
+spam
 ZeroDivisionError
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 Exception