[editor] making absolue area for drag and drop of sql file in editor

desktop/libs/notebook/src/notebook/static/notebook/less/editor2.less

@@ -1062,7 +1062,7 @@
     height: 100%;
     left: 0;
     opacity: .5;
-    position: fixed;
+    position: absolute;
     width: 100%;
     top:0;
     z-index: 10000;

desktop/libs/notebook/src/notebook/static/notebook/less/notebook.less

@@ -806,7 +806,7 @@
     height: 100%;
     left: 0;
     opacity: .5;
-    position: fixed;
+    position: absolute;
     width: 100%;
     top:0;
     z-index: 10000;