thermostat: bug: fix (again) dayOfWeek matching

soft/thermostat/src/mainwindow.cpp

@@ -132,10 +132,10 @@ double MainWindow::get_target_temperature(int room_idx)
 
 	/*
 	 * dayOfWeek() returns 1 for monday, 7 for sunday.
-	 * so dow <<= 1 gives 0 for monday, 6 for sunday.
+	 * so dow -= 1 gives 0 for monday, 6 for sunday.
 	 * And (1 << dow) gives the day of week as a bit field
 	 */
-	dow <<= 1;
+	dow -= 1;
 	for (int i = 0; i < r->progs.count(); i++) {
 		p = &(r->progs.at(i));
 		if ((1 << dow) & p->DoW) {