grey out text color of key creation date for disabled items

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/adapter/KeyAdapter.java

@@ -187,6 +187,7 @@ public class KeyAdapter extends CursorAdapter {
 
                     mCreationDate.setText(context.getString(R.string.label_key_created,
                             dateTime));
+                    mCreationDate.setTextColor(context.getResources().getColor(textColor));
                     mCreationDate.setVisibility(View.VISIBLE);
                 } else {
                     mCreationDate.setVisibility(View.GONE);