Fix condition that checks for Python 3.8

Author: mwcraig

vpython/no_notebook.py

@@ -249,7 +249,7 @@ def onClose(self, wasClean, code, reason):
         raise RuntimeError('The pyqt browser cannot be used on Windows. '
                            'Please use the default browser instead by '
                            'removing set_browser("pyqt") from your code.')
-    elif sys.version_info.major == 3 and sys.version_info.minor >= 7:
+    elif sys.version_info.major == 3 and sys.version_info.minor >= 8:
         raise RuntimeError('The pyqt browser cannot be used on Python 3.8. '
                            'Please use the default browser instead by '
                            'removing set_browser("pyqt") from your code.')