Apply suggestion from @weizhouapache

Author: weizhouapache

engine/api/src/main/java/org/apache/cloudstack/engine/orchestration/service/NetworkOrchestrationService.java

@@ -93,7 +93,7 @@ public interface NetworkOrchestrationService {
 
     ConfigKey<Integer> DhcpLeaseTimeout = new ConfigKey<>("Network", Integer.class, "dhcp.lease.timeout", "0",
             "DHCP lease time in seconds for VMs. Use 0 for infinite lease time (default). A non-zero value sets the lease duration in seconds.",
-            true, ConfigKey.Scope.Zone, "0-");
+            true, ConfigKey.Scope.Zone);
 
     ConfigKey<Boolean> PromiscuousMode = new ConfigKey<>("Advanced", Boolean.class, "network.promiscuous.mode", "false",
             "Whether to allow or deny promiscuous mode on NICs for applicable network elements such as for vswitch/dvswitch portgroups.", true);