Run index task in ldap updater only when needed

When LDAP updater detected an update instruction in indexing tree, it run
an indexing task and waited until it ends. However, the task was run
regardless of the update instruction result. This lead to unnecessary
index tasks being defined and waited for which makes the whole LDAP
last longer.

Execute indexing task only when an index add/update instruction is
successful.

https://fedorahosted.org/freeipa/ticket/2866

ipaserver/install/ldapupdate.py

@@ -754,6 +754,8 @@ class LDAPUpdate:
 
         self.print_entity(entry, "Final value after applying updates")
 
+        added = False
+        updated = False
         if not found:
             # New entries get their orig_data set to the entry itself. We want to
             # empty that so that everything appears new when generating the
@@ -773,13 +775,13 @@ class LDAPUpdate:
                             self.info("Parent DN of %s may not exist, cannot create the entry",
                                     entry.dn)
                             return
+                added = True
                 self.modified = True
             except Exception, e:
                 self.error("Add failure %s", e)
         else:
             # Update LDAP
             try:
-                updated = False
                 changes = self.conn.generateModList(entry.origDataDict(), entry.toDict())
                 if (entry.dn == DN(('cn', 'schema'))):
                     d = dict()
@@ -805,13 +807,14 @@ class LDAPUpdate:
                 self.error("Update failed: %s", e)
                 updated = False
 
-            if (DN(('cn', 'index')) in entry.dn and
-                DN(('cn', 'userRoot')) in entry.dn):
-                taskid = self.create_index_task(entry.getValue('cn'))
-                self.monitor_index_task(taskid)
-
             if updated:
                 self.modified = True
+
+        if entry.dn.endswith(DN(('cn', 'index'), ('cn', 'userRoot'),
+                                ('cn', 'ldbm database'), ('cn', 'plugins'),
+                                ('cn', 'config'))) and (added or updated):
+            taskid = self.create_index_task(entry.getValue('cn'))
+            self.monitor_index_task(taskid)
         return
 
     def _delete_record(self, updates):