Fix typo in system header.
@@ -46,7 +46,7 @@ extern void papplSystemDelete(pappl_system_t *system) _PAPPL_PUBLIC;
extern pappl_printer_t *papplSystemFindPrinter(pappl_system_t *system, const char *resource, int printer_id) _PAPPL_PUBLIC;
extern int papplSystemGetDefaultPrinterId(pappl_system_t *system) _PAPPL_PUBLIC;
extern int papplSystemGetNextPrinterId(pappl_system_t *system) _PAPPL_PUBLIC;
-extern const char papplSystemGetSessionKey(pappl_system_t *system) _PAPPL_PUBLIC;
+extern const char *papplSystemGetSessionKey(pappl_system_t *system) _PAPPL_PUBLIC;
extern void papplSystemInitDNSSD(pappl_system_t *system) _PAPPL_PUBLIC; // Why not part of creating the system?
extern void papplSystemIteratePrinters(pappl_system_t *system, pappl_printer_cb_t cb, void *data) _PAPPL_PUBLIC;
extern void papplSystemRemoveResource(pappl_system_t *system, const char *path) _PAPPL_PUBLIC;
