Fixed missing {has_other_subnet} from subnet.

Had been introduced in 67ca5ab338.
Test checks for too optimistic optimization.
Added test for managed hosts.
Fixed warning.
v3.037

 - Added support for managed Linux hosts to generate ACLs for servers.
   Example
    host:h = {
     ip = 1.2.3.4;
     model = Linux;
     managed;
     hardware = eth1;
    }
   This creates a file "host:h" with IPTables rules in out-directory.
 - When generating rules for IPTables, the INPUT chain now gets a rule
   to accept traffic on interface lo: "-A INPUT -j ACCEPT -i lo".
 - Fixed too optimistic secondary optimization,
   with network S2 in one zone, S1 and N in other zone and S2 < S1 < N.
   (Bug was introduced in v3.035).