Made disabled login button have clearer text

Having a disabled login button with almost transparent text makes it hard to read, thus not as aesthetic as a clearer label. IMHO transparent text is not that good an indicator that the button is unclickable. Besides, everyone knows that they have to enter a password before they log in, as is evident by the password input, and by the fact that they created a password.

kde/sddm/Login.qml

@@ -111,7 +111,7 @@ SessionManagementScreen {
         contentItem: Text {
             text: loginButton.text
             font: loginButton.font
-            opacity: enabled ? 1.0 : 0.3
+            opacity: enabled ? 1.0 : 0.8
             color: "#ffffff"
             horizontalAlignment: Text.AlignHCenter
             verticalAlignment: Text.AlignVCenter