networkAgent: Don't allow ellipsization of Password label

We don't want password entries to grow when entering more characters
that fit the available width; as labels' ClutterText ellipsizes by
default, the password labels allow entries to grow by shrinking.
Setting the appropriate ellipsize mode fixes this.

https://bugzilla.gnome.org/show_bug.cgi?id=708324

js/ui/components/networkAgent.js

@@ -83,6 +83,7 @@ const NetworkSecretDialog = new Lang.Class({
             let secret = this._content.secrets[i];
             let label = new St.Label({ style_class: 'prompt-dialog-password-label',
                                        text: secret.label });
+            label.clutter_text.ellipsize = Pango.EllipsizeMode.NONE;
 
             let reactive = secret.key != null;