Preferences: Parameters of Methods
Here you are able to edit some context menu items that will appear when
right clicking while setting the parameters of a method. In the context
menu, you find the item "Reset to defaults" with which you can re install
the default settings.

By pressing "OK" you confirm changes, "Cancel" deletes any changes.
Some made changes can only be applied after restarting Jedi because
already used context menues can not be changed immediately.