change the old pictures showing fusiondirectory 1.0.8 in the manual

Hello,

we have some very old pictures int the dev manual that should be replaced

https://fusiondirectory-developer-documentation.readthedocs.io/en/1.4/fusiondirectory/pluginsystem/start.html#displaying-the-plugin-in-fusiondirectory

https://fusiondirectory-developer-documentation.readthedocs.io/en/1.4/fusiondirectory/pluginsystem/attributes.html#usersattribute