Perf: Add missing index on projet_task_time table.

htdocs/install/mysql/tables/llx_projet_task_time.key.sql

+-- ===========================================================================
+-- Copyright (C) 2014 Laurent Destailleur  <eldy@users.sourceforge.net>
+--
+-- This program is free software; you can redistribute it and/or modify
+-- it under the terms of the GNU General Public License as published by
+-- the Free Software Foundation; either version 3 of the License, or
+-- (at your option) any later version.
+--
+-- This program is distributed in the hope that it will be useful,
+-- but WITHOUT ANY WARRANTY; without even the implied warranty of
+-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+-- GNU General Public License for more details.
+--
+-- You should have received a copy of the GNU General Public License
+-- along with this program. If not, see <http://www.gnu.org/licenses/>.
+--
+-- ===========================================================================
+
+ALTER TABLE llx_projet_task_time ADD INDEX idx_projet_task_time_task (fk_task);
+ALTER TABLE llx_projet_task_time ADD INDEX idx_projet_task_time_date (task_date);
+ALTER TABLE llx_projet_task_time ADD INDEX idx_projet_task_time_datehour (task_datehour);
+