HPCC-17183 Fix 'Sort by ManagedBy' not working For GroupQuery

The '@groupOwner' should be used to sort on ManagedBy.

Signed-off-by: wangkx <kevin.wang@lexisnexis.com>

system/security/LdapSecurity/ldapconnection.cpp

@@ -69,7 +69,7 @@ const char* getUserFieldNames(UserField field)
     return NULL;
 }
 
-const char* GroupFieldNames[] = { "@name", "@managedby", "@desc" };
+const char* GroupFieldNames[] = { "@name", "@groupOwner", "@desc" };
 
 const char* getGroupFieldNames(GroupField field)
 {