Fix GSL_DISABLE_DEPRECAED macro in setup.py

<div id="comment:0"></div>

Francois noted in http://groups.google.com/group/sage-devel/browse_thread/thread/4a902c07ebb7c45d that:

```
In sage-2.10.3.rc3 in the top setup.py at line 430 we have:
define_macros = [('GSL_DISABLE_DEPRECAED','1')]
For those who can't spot it, it miss a 'T'. 
```


Component: **build**

_Issue created by migration from https://trac.sagemath.org/ticket/2459_

