Display security state when asking for password

Indicate to the user how secure the transport channel is so they
can avoid entering their password for untrusted sites.
diff --git a/vncviewer/UserDialog.h b/vncviewer/UserDialog.h
index c6756a8..b62ba7f 100644
--- a/vncviewer/UserDialog.h
+++ b/vncviewer/UserDialog.h
@@ -31,7 +31,7 @@
 
   // UserPasswdGetter callbacks
 
-  void getUserPasswd(char** user, char** password);
+  void getUserPasswd(bool secure, char** user, char** password);
 
   // UserMsgBox callbacks