Revert "fix: MPR initialization (#1062)" (#1064)

This reverts commit b03739428f.

platform/viewer/src/components/ViewportGrid/ViewportGrid.js

@@ -32,11 +32,6 @@ const ViewportGrid = function(props) {
 
   const ViewportPanes = layout.viewports.map((layout, viewportIndex) => {
     const displaySet = viewportData[viewportIndex];
-
-    if (!displaySet) {
-      return null;
-    }
-
     const data = {
       displaySet,
       studies,
@@ -113,9 +108,6 @@ ViewportGrid.propTypes = {
   setViewportData: PropTypes.func.isRequired,
   studies: PropTypes.array,
   children: PropTypes.node,
-  defaultPlugin: PropTypes.string,
-  numRows: PropTypes.number,
-  numColumns: PropTypes.number,
 };
 
 ViewportGrid.defaultProps = {