PermissionsDao: Add clearForPage()

database/permissionsdaosqlite.h

@@ -10,6 +10,7 @@ class PermissionsDaoSqlite : public PermissionsDao, protected SqliteDao
 
 	std::optional<Permissions> find(std::string pagename, std::string username) override;
 	virtual void save(std::string pagename, std::string username, Permissions perms) override;
+	virtual void clearForPage(std::string pagename) override;
 	using SqliteDao::SqliteDao;
 };