SNMP Generic ICMP ping interface can not be changed

Steps to reproduce:

1. Create a host (for a printer for example)
2. Add a Zabbix Agent interface
3. Add a SNMP interface
4. Apply the "Generic SNMP" template
5. Edit the item "ICMP ping" on the host, it is impossible to change the interface, and you can't delete the agent interface event if the SNMP interface is available.

Expected:
When two interface are configured, allow to delete zabbix agent, even if ICMP Ping use it (and switch ICMP ping to the second interface (snmp)).

Idealy, Generic SNMP ICMP ping should depend on the SNMP interface, not the Zabbix agent one.