Fixed offset plaintext password button

This affects the position of all cbi buttons in the UI by 0.5rem, if this doesn't bother anyone I think it's a reasonable change to make sure things line up properly.

luasrc/gaya/gaya.css

@@ -2586,7 +2586,6 @@ strong {
       font-size: 0.8rem;
       padding: 0.3rem 0.6rem;
       position: relative;
-      bottom: -0.5rem;
     }
     .label,
     [data-indicator] {