[gnome-shell] Revert "authPrompt: Don't hide the caps lock warning label"

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 41da4b06816eb795803161d5d63fba5a934aba6b
Author: Florian Müllner <fmuellner gnome org>
Date:   Fri Feb 14 20:50:59 2020 +0100

    Revert "authPrompt: Don't hide the caps lock warning label"
    
    Using the opacity to control the label's visibility doesn't work
    correctly, as CapsLockWarning itself changes the opacity when
    the caps-lock state changes.
    
    This reverts commit 9f5f6aa9b2c8f5f055a3c3b6ff2270a79c1b5e69.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/issues/2215

 js/gdm/authPrompt.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/js/gdm/authPrompt.js b/js/gdm/authPrompt.js
index 42638bee5f..6edb2694a5 100644
--- a/js/gdm/authPrompt.js
+++ b/js/gdm/authPrompt.js
@@ -205,7 +205,7 @@ var AuthPrompt = GObject.registerClass({
             this._mainBox.replace_child(this._entry, this._textEntry);
             this._entry = this._textEntry;
         }
-        this._capsLockWarningLabel.opacity = secret ? 0 : 255;
+        this._capsLockWarningLabel.visible = secret;
     }
 
     _onAskQuestion(verifier, serviceName, question, secret) {