Vdropdown: CSS border issue when reference is not a button + click trigger

[enodr]

We have a strange CSS issue when using the vdropdown component with a div as reference instead of a button and the click trigger.

As you can see the popper div has a border which disappears when any button is clicked in the browser. Under firefox this border appears in red. This is hard to debug as any click on a button in the browser will make the border disappear (so no luck opening the inspector in the debug console).

Steps to reproduce:

• Use a vdropdown with a div as reference (not a button)
• trigger set to "click"
• the popper will have a default border which disappears on any button click inside the browser (even the toolbar buttons will make the border disappear).

Note: the problem does not appear when using "hover" as a trigger, nor with a button as the reference.

[enodr]

Just realized this is a duplicate of: #848