Update spyder3 to 3.3.6
Changes
- Fix Text in help search bar becomes selected once help is displayed
- Avoid an error when profdata is None in Profiler
- Fix completion plugins listening to external hosts
- Require spyder-kernels 0.5.0 or above in setup.py
- Remove usage of QTextCodec because it's not really needed
- Catch error when loading kernel connection file
- Catch an error when disconnecting a signal in calltip widget
- Catch error when pressing the link of a traceback in IPython console
- Require pyqtwebengine only in Python 3
- Fix Help plugin string validation for the console
- Add preference to show/hide cmd windows generated by the subprocess module