Keep saved username/password between connects

The UserDialog object is now only created for a single connection at a
time, which means we need to make sure the cached username and password
survive until the subsequent object.

vncviewer/UserDialog.cxx

@@ -57,6 +57,9 @@ using namespace rfb;
 static Fl_Pixmap secure_icon(secure);
 static Fl_Pixmap insecure_icon(insecure);
 
+std::string UserDialog::savedUsername;
+std::string UserDialog::savedPassword;
+
 static long ret_val = 0;
 
 static void button_cb(Fl_Widget *widget, long val) {

vncviewer/UserDialog.h

@@ -38,8 +38,8 @@ class UserDialog
   void resetPassword();
 
 private:
-  std::string savedUsername;
-  std::string savedPassword;
+  static std::string savedUsername;
+  static std::string savedPassword;
 };
 
 #endif