Problem description: In case if a previously discovered LLD rule is no longer discovered, all of its prototypes are instantly removed even if the "Delete lost resources" field is set to time specific time period.
Server log for the below described scenario with DebugLevel = 4: zabbix_server_unexpected_prototypes_removal.log

Steps to reproduce:

1. Import the following host (nhost name = test2): host_for_lost_resource_issue_test.yaml
2. Check configuration of LLD rule "Root level LLD" - Notice that "Delete lost resources" is set to 7 days.
3. Send the following value to LLD rule with key "trap":

   ./bin/zabbix_sender -z 127.0.0.1 -s test2 -k trap -o '{"data":[{"level_0":"01"}]}'
   

1. Open the list of LLD rules on host "test2"
2. Notice that an LLD rule with key "lld_trap[01]" was discovered, and that it has 1 prototype of each type (item/trigger/graph/host/discovery prototypes)
3. Send a different value to LLD rule with key "trap":

   ./bin/zabbix_sender -z 127.0.0.1 -s test2 -k trap -o '{"data":[{"level_0":"02"}]}'
   

1. Check the list of LLD rules on host "test2"

Result: even though the LLD rule with key "lld_trap[01]" is still there, all of its prototypes have disappeared.
Expected: if "Delete lost resources" is set to delete lost resources after some period of time, all discovered entities should be deleted only after this time period has passed.