sticker/Database: remove C-style (void)

src/sticker/StickerDatabase.cxx

@@ -149,7 +149,7 @@ sticker_global_init(Path path, Error &error)
 }
 
 void
-sticker_global_finish(void)
+sticker_global_finish()
 {
 	if (sticker_db == nullptr)
 		/* not configured */
@@ -165,7 +165,7 @@ sticker_global_finish(void)
 }
 
 bool
-sticker_enabled(void)
+sticker_enabled()
 {
 	return sticker_db != nullptr;
 }

src/sticker/StickerDatabase.hxx

@@ -62,14 +62,14 @@ sticker_global_init(Path path, Error &error);
  * Close the sticker database.
  */
 void
-sticker_global_finish(void);
+sticker_global_finish();
 
 /**
  * Returns true if the sticker database is configured and available.
  */
 gcc_const
 bool
-sticker_enabled(void);
+sticker_enabled();
 
 /**
  * Returns one value from an object's sticker record.  Returns an