replica install fails with domain level 1

when updating an replication agreement from a toplogy segment an incorrect default value was used for bindmethod.
    Only attributes explicitely set in the segment should be applied.
    At shutdown the server could crash because the plugin was called after it was stopped.

    https://fedorahosted.org/freeipa/ticket/5035

Reviewed-By: Petr Vobornik <pvoborni@redhat.com>
Reviewed-By: Thierry Bordaz <tbordaz@redhat.com>

daemons/ipa-slapi-plugins/topology/topology_agmt.c

@@ -70,7 +70,8 @@ int
 ipa_topo_agmt_new(char *hostname, TopoReplica *conf, TopoReplicaAgmt *agmt)
 {
     int ret = 0;
-    if (strcasecmp(agmt->repl_bind_method,"SASL/GSSAPI") == 0) {
+    if ((agmt->repl_bind_method == NULL) /* use GSSAPI as default */ ||
+         (strcasecmp(agmt->repl_bind_method,"SASL/GSSAPI") == 0)) {
         ret = ipa_topo_agmt_setup(hostname, conf, agmt, 1);
     } else {
         ret = ipa_topo_agmt_setup(hostname, conf, agmt, 0);

daemons/ipa-slapi-plugins/topology/topology_init.c

@@ -225,12 +225,12 @@ static int
 ipa_topo_close(Slapi_PBlock * pb)
 {
 
+    ipa_topo_set_plugin_active(0);
     slapi_config_remove_callback(SLAPI_OPERATION_SEARCH, DSE_FLAG_PREOP,
             "", LDAP_SCOPE_BASE, "(objectclass=*)", ipa_topo_rootdse_search);
     slapi_unregister_backend_state_change((void *)ipa_topo_be_state_change);
     ipa_topo_free_plugin_config();
     return 0;
-
 }
 static int
 ipa_topo_rootdse_init(Slapi_PBlock *pb)

daemons/ipa-slapi-plugins/topology/topology_util.c

@@ -329,9 +329,6 @@ ipa_topo_util_agmt_from_entry(Slapi_Entry *entry, char *replRoot, char *fromHost
             ipa_topo_util_set_segm_attr(agmt, mattrs[i], mval);
         }
     }
-    if (agmt->repl_bind_method == NULL) {
-        agmt->repl_bind_method = slapi_ch_strdup("SASL/GSSAPI");
-    }
     return agmt;
 }
 TopoReplicaSegment *