Fix render validation items on keypress event at login form
    
    There are many no needed render callings which are performed
    on each keypress event at login form. It is enough to update
    validation items on "CapsLock" state change.
    
    Fixes: https://pagure.io/freeipa/issue/7679
    Reviewed-By: Serhii Tsymbaliuk <stsymbal@redhat.com>