Do not register removed node on agent restart (netdata#19609)

* If unregistered during startup and it was removed by cli or cleanup, do not register again

* Code cleanup

src/database/sqlite/sqlite_aclk.c

@@ -131,7 +131,7 @@ static int create_host_callback(void *data, int argc, char **argv, char **column
     char guid[UUID_STR_LEN];
     uuid_unparse_lower(*(nd_uuid_t *)argv[IDX_HOST_ID], guid);
 
-    if (is_ephemeral && rrdhost_free_ephemeral_time_s && age > rrdhost_free_ephemeral_time_s) {
+    if (is_ephemeral && ((!is_registered && last_connected == 1) || (rrdhost_free_ephemeral_time_s && age > rrdhost_free_ephemeral_time_s))) {
         netdata_log_info(
             "%s ephemeral hostname \"%s\" with GUID \"%s\", age = %ld seconds (limit %ld seconds)",
             is_registered ? "Loading registered" : "Skipping unregistered",
@@ -141,7 +141,7 @@ static int create_host_callback(void *data, int argc, char **argv, char **column
             rrdhost_free_ephemeral_time_s);
 
         if (!is_registered)
-            return 0;
+           goto done;
     }
 
     struct rrdhost_system_info *system_info = rrdhost_system_info_create();
@@ -196,6 +196,8 @@ static int create_host_callback(void *data, int argc, char **argv, char **column
     internal_error(true, "Adding archived host \"%s\" with GUID \"%s\" node id = \"%s\"  ephemeral=%d",
                    rrdhost_hostname(host), host->machine_guid, node_str, is_ephemeral);
 #endif
+
+done:
     return 0;
 }