python plugin: Cast pointer to `void *' to work around strict aliasing problems.

python plugin: Cast pointer to `void *' to work around strict aliasing problems.

python.c: In function `cpy_write_callback':
python.c:349: warning: dereferencing type-punned pointer will break strict-aliasing rules
python.c: In function `cpy_notification_callback':
python.c:368: warning: dereferencing type-punned pointer will break strict-aliasing rules
python.c: In function `cpy_oconfig_to_pyconfig':
python.c:842: warning: dereferencing type-punned pointer will break strict-aliasing rules
python.c: In function `cpy_config':
python.c:887: warning: dereferencing type-punned pointer will break strict-aliasing rules
python.c:888: warning: dereferencing type-punned pointer will break strict-aliasing rules
python.c:889: warning: dereferencing type-punned pointer will break strict-aliasing rules