WebAPI: Don't throw error on edit category

[vafada]

Closes #23845

Do not check the return value of BitTorrent::Session::instance()->setCategoryOptions()

This change replicates how the native client works:

qBittorrent/src/gui/torrentcategorydialog.cpp

Lines 125 to 128 in d66fa17

	connect(dialog, &TorrentCategoryDialog::accepted, parent, [dialog, categoryName]()
	{
	Session::instance()->setCategoryOptions(categoryName, dialog->categoryOptions());
	});