Filter machine types by GLPI ID

For the filter, in the `main` section of `/etc/mmc/plugins/glpi.ini.local`, add:
filter_on = <criterion>

#Display only computers that match one of these filters:
* state
* type
* entity
* autoupdatesystems_id

#Each filter may contain a list of values separated by a pipe
#Filters are IDs separated by spaces

i.e., state=1 type=2|3|7 entity=2|5
filter_on = state=3