Steps to reproduce:
1) Create several hosts with status - enabled.
2) Navigate to proxy page.
3) There could be 0 proxies (empty list).
4) Open "Disable hosts" elements and remove disabled.

5) Now click on enabled "Disable hosts" button.

Result:
ALL hosts are disabled. Even if you have no proxies at all in Zabbix.

Expected:
Error message like -
Invalid parameter "/1/request/proxy_hostids": cannot be empty.