Ticket 47969 - COS memory leak when rebuilding the cache

Bug Description:  When the COS cache is released, not all of the schema
                  objectclasses are freed.  So every time we rebuild the
                  COS cache we leak memory.

Fix Description:  After we free the schema attributes, the very first
                  attribute still needs to be freed.  It is not freed
                  initially because of the duplicate checking logic, so
                  it is now done after the loop.

https://fedorahosted.org/389/ticket/47969

Reviewed by: nhosoi(Thanks!)

ldap/servers/plugins/cos/cos_cache.c

@@ -1864,6 +1864,8 @@ static void cos_cache_del_schema(cosCache *pCache)
 			}
 		}
 	}
+	/* Finally, remove the first attribute's objectclass list */
+	cos_cache_del_attrval_list(&(pCache->ppAttrIndex[0]->pObjectclasses));
 
 	LDAPDebug( LDAP_DEBUG_TRACE, "<-- cos_cache_del_schema\n",0,0,0);
 }