bring upload status container to the front

customize.dist/src/less/cryptpad.less

@@ -617,7 +617,7 @@ noscript {
     opacity: 0.7;
     font-family: Ubuntu,Georgia,Cambria,serif;
     box-sizing: border-box;
-    z-index:10;
+    z-index:10000;
     display: none;
     #uploadStatus {
         width: 80vw;