Show supported file types in upload file selector

By default, all file types are shown, but the user now has the option of
filtering only by supported types in the file selector dialog.

Signed-off-by: Stefan Reiter <s.reiter@proxmox.com>
Acked-by: Dominik Csapak <d.csapak@proxmox.com>

www/manager6/storage/ContentView.js

@@ -218,7 +218,14 @@ Ext.define('PVE.storage.Upload', {
 		    xtype: 'filefield',
 		    name: 'filename',
 		    buttonText: gettext('Select File...'),
-		    allowBlank: false
+		    allowBlank: false,
+		    listeners: {
+			afterrender: function(cmp) {
+			    cmp.fileInputEl.set({
+				accept: '.img, .iso'
+			    });
+			}
+		    }
 		},
 		pbar
 	    ]