Return eye-icon to its place when validation message is shown

Making eye-icon properly positioned relies on its parent having
'has-feedback' class - which makes the parent to obey 'position:
relative' and thus eye-icon with its 'position: absolute' is properly
positioned within it.

Change-Id: I69ce13e1e3fc9674c4f25e7d04d79a3f550014a6
Closes-Bug: #1386126
(cherry picked from commit 6ffebb6d200a071774048e792752cd201a5c6d0d)
Merge "Return eye-icon to its place when validation message is shown" into stable/juno