Changed back 'loginbox' to 'login' to match v1 naming

May otherwise result in BC issues with v1 themes.

Started this in https://github.com/e107inc/e107/commit/976c386cf25b170e5cb6311fa8e0c3f42dae1994#diff-99152c2c22704b20b8cc720f89b9f005 but forgot these two.