fix height and scrollbar styling of file list

Author: telamonian

src/style/FileListStyle.ts

@@ -3,11 +3,9 @@ import { style } from 'typestyle';
 export const fileListWrapperClass = style({
   height: 'auto',
   minHeight: '150px',
-  maxHeight: '400px',
-  paddingBottom: '40px',
 
   overflow: 'hidden',
-  overflowY: 'scroll'
+  overflowY: 'auto'
 });
 
 export const notebookFileIconStyle = style({