DEPR: remove some Exception.message usage
this is pretty old code, I think you you simply eliminate the try:excepts: here entirey: https://github.com/pydata/pandas/blob/master/pandas/computation/tests/test_eval.py#L52

```
In [4]: pd.test(raise_warnings='release')
Running unit tests for pandas
pandas version 0.17.1+289.g0977cb6
numpy version 1.10.2
pandas is installed in pandas
Python version 2.7.11 |Continuum Analytics, Inc.| (default, Dec  6 2015, 18:57:58) [GCC 4.2.1 (Apple Inc. build 5577)]
nose version 1.3.7
...................................................pandas/computation/tests/test_eval.py:53: DeprecationWarning: BaseException.message has been deprecated as of Python 2.6
  msg = e.message
pandas/computation/tests/test_eval.py:53: DeprecationWarning: BaseException.message has been deprecated as of Python 2.6
  msg = e.message
...............pandas/computation/tests/test_eval.py:310: DeprecationWarning: BaseException.message has been deprecated as of Python 2.6
  emsg = e.message
S..............pandas/computation/tests/test_eval.py:310: DeprecationWarning: BaseException.message has been deprecated as of Python 2.6
  emsg = e.message
S............................................................................................................................................................................................................
```
