Description of problem:
After some of the recent updates mate-menu is completely broken, it displays a python traceback instead of the actual menu.

Version-Release number of selected component (if applicable):
mate-menu-18.04.3-1.fc29.noarch

How reproducible:
always

Steps to Reproduce:
1. Open mate-menu

Actual results:
Menu with traceback instead of applications.

Expected results:
Menu with applications.

Full traceback as displayed in GUI:

Traceback (most recent call last):

  File "/usr/lib/mate-menu/mate-menu.py", line 202, in PopulatePlugins
    exec("from {plugin_module} import pluginclass".format(plugin_module=plugin_module))

  File "<string>", line 1, in <module>

  File "/usr/lib/python2.7/site-packages/mate_menu/plugins/applications.py", line 38, in <module>
    import matemenu

ImportError: No module named matemenu