C0103 fixes 1

this part contains the changes on local variables
```bash
renelvon @ merchant ~ % python2
Python 2.7.6 (default, Mar 22 2014, 22:59:56) 
[GCC 4.8.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> issubclass(RuntimeError, Exception)
True
```
... which means you could also have used `exc` here. Just keep that in mind, don't change anything.