change instance-erp5-input-schema.json without result json document change.

Hello @vpelletier

i am not sure i correctly understand this slapos schema but i wanted to give an example how to properties in json schema can be connected to each other. could you please review.

the purpose of mr: user has one choice instead of two choices in ui. before change type field and server field were not connected and user had to select type independently of server select.