Fixes the Bleed through of the Submission box Resize Handle by increasing the Z…

Fixes the Bleed through of the Submission box Resize Handle by increasing the Z score of the modal which it was bleeding through.

openassessment/xblock/static/sass/oa/utilities/_shame.scss

@@ -206,5 +206,5 @@
 }
 
 .modal-lg.modal-window.confirm.openassessment_modal_window{
-  z-index: 100000;
+  z-index: 100000; 
 }