erp5_production_planning: wait for matrixbox fully displayed

bt5/erp5_production_planning/SkinTemplateItem/portal_skins/erp5_production_planning/matrix_dynamic_total_line_column.js.js

@@ -115,8 +115,10 @@ function observe(mutationsList) {
       for (i = 0; i < len; i += 1) {
         node = mutation.addedNodes[i];
         if (node.nodeType === Node.ELEMENT_NODE) {
-          if (node.getAttribute('class') == 'field matrixbox_production_planning') {
-            addTotalLineColumnToMatrixBox(node);
+          // Make sure matrixbox is fully displayed
+          if (node.getAttribute('class') == 'Data footer') {
+             var matrixbox = document.querySelector('.matrixbox_production_planning');
+            addTotalLineColumnToMatrixBox(matrixbox);
             observer.disconnect();
           }
         }