Fix Typo

gui/qt/main_window.py

@@ -1182,7 +1182,7 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, PrintError):
             self.fee_adv_controls.setVisible(False)
 
         self.preview_button = EnterButton(_("Preview"), self.do_preview)
-        self.preview_button.setToolTip(_('Display the details of your transactions before signing it.'))
+        self.preview_button.setToolTip(_('Display the details of your transaction before signing it.'))
         self.send_button = EnterButton(_("Send"), self.do_send)
         self.clear_button = EnterButton(_("Clear"), self.do_clear)
         buttons = QHBoxLayout()