Hide username and password in eg2 when screen is narrow

Hide username and password in eg2 when screen is narrow

The Angular staff client navbar doesn't collapse when the screen is narrow
but currently the username and password can wrap, pushing the navbar over
the content. This patch doesn't add a collapsing navbar but hiding the user
information does at least stop the navbar from growing.

Signed-off-by: Jason Boyer <JBoyer@equinoxOLI.org>
Signed-off-by: rfrasur <rfrasur@library.in.gov>
Signed-off-by: Mike Rylander <mrylander@gmail.com>