This fixes a build failure against Python 2.4 by casting away "const"
on the second argument to PyObject_GetAttrString. Similar casts to
support Python 2.4 were already present in a number of other places.
gdb/
2014-03-16 Ulrich Weigand <uweigand@de.ibm.com>
* python/py-value.c (get_field_flag): Cast flag_name argument to
PyObject_GetAttrString to support Python 2.4.