better help msg

gui/qt/main_window.py

@@ -621,7 +621,11 @@ class ElectrumWindow(QMainWindow):
         self.expires_combo = QComboBox()
         self.expires_combo.addItems(map(lambda x:x[0], expiration_values))
         self.expires_combo.setCurrentIndex(1)
-        msg = _('Expiration date of your request. This information is not included in the Bitcoin address nor in the QR code; the recipient will see it only if you send them a complete request.')
+        msg = ' '.join([
+            _('Expiration date of your request.'),
+            _('This information is seen by the recipient if you send them a signed payment request.'),
+            _('Expired requests have to be deleted manually from your list, in order to free the corresponding Bitcoin addresses'),
+        ])
         grid.addWidget(HelpLabel(_('Expires in'), msg), 3, 0)
         grid.addWidget(self.expires_combo, 3, 1)
         self.expires_label = QLineEdit('')