Steps to reproduce:

1. Create Zabbix agent LLD, save it
2. Open saved LLD 
3. Observe that Execute now and Test buttons are enabled - EXPECTED
4. Change LLD type to Trapper, don't save form yet
5. Observe that Test button became disabled, but Execute now  is still enabled - NOT EXPECTED
6. Press Execute now - get green message "Request sent successfully" - NOT EXPECTED

Expected:
Both Execute now and Test buttons are changing correspondingly to type change.