bpo-28769 changed PyUnicode_AsUTF8() return type from const char* to
char* in Python 3.7, but tm_zone field type of the tm structure is
char* on FreeBSD.
Cast PyUnicode_AsUTF8() to char* in gettmarg() to fix the warning:
Modules/timemodule.c:443:20: warning: assigning to 'char *'
from 'const char *' discards qualifiers
if (Py_TYPE(args) == &StructTimeType) {
PyObject *item;
item = PyTuple_GET_ITEM(args, 9);
- p->tm_zone = item == Py_None ? NULL : PyUnicode_AsUTF8(item);
+ p->tm_zone = item == Py_None ? NULL : (char*)PyUnicode_AsUTF8(item);
item = PyTuple_GET_ITEM(args, 10);
p->tm_gmtoff = item == Py_None ? 0 : PyLong_AsLong(item);
if (PyErr_Occurred())