polkitAgent: Do not set initial focus in the password entry

The password entry can be hidden if the user has no password set, but
setting the initial focus to it will result in the entry responding to
the "activate" and signals.
Besides, with the logic that the dialog follows, setting the initial
focus in the entry is redundant, because the focus is also set in the
entry upon showing it.

js/ui/components/polkitAgent.js

@@ -123,7 +123,6 @@ var AuthenticationDialog = new Lang.Class({
 
         this._passwordBox.add(this._workSpinner.actor);
 
-        this.setInitialKeyFocus(this._passwordEntry);
         this._passwordBox.hide();
 
         this._errorMessageLabel = new St.Label({ style_class: 'prompt-dialog-error-label' });