pidgin/pidgin

Fix the prototypes for purple_attachment_[gs]et_size to match the actual implementation

Make prototypes for purple_attachment_[gs]et_size match the implementation.

Testing Done:
Compiled locally that wasn't showing the warning/error. I actually found it while figuring out why the macos build was failing.

Reviewed at https://reviews.imfreedom.org/r/138/
/*
* finch
*
* Finch is the legal property of its developers, whose names are too numerous
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* source distribution.
*
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* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <https://www.gnu.org/licenses/>.
*/
#ifndef FINCH_H
#define FINCH_H
#ifndef FINCH_GLOBAL_HEADER_INSIDE
#define FINCH_GLOBAL_HEADER_INSIDE
#endif
@FINCH_H_INCLUDES@
#undef FINCH_GLOBAL_HEADER_INSIDE
#endif /* FINCH_H */