Download button should be invisible before password input

[christaikobo]

Description

When visiting a share link, the "download" button is visible before password is entered, which can cause confusion for users.

Also there is a red warning which might also causing confusion or even panic. Red warning should be reserved for when something goes wrong, but the first time you visit the share page, nothing is wrong, it's just password is not entered YET.

Expected behaviour
Hide download button before password is entered, do now show red warning.

[gtsteffaniak]

will come in 0.8.6