Fixed the CSS issue causing extra space at the bottom of maintenance backup dialog.

web/pgadmin/browser/static/js/node.js

@@ -528,7 +528,7 @@ define('pgadmin.browser.node', [
         isLayoutMember: false,
         canMaximise: true,
         elContainer: true,
-        content: '<div class="obj_properties container-fluid"><div role="status" class="pg-panel-message">' + gettext('Please wait while we fetch information about the node from the server...') + '</div></div>',
+        content: '<div class="obj_properties container-fluid h-100"><div role="status" class="pg-panel-message">' + gettext('Please wait while we fetch information about the node from the server...') + '</div></div>',
         onCreate: function(myPanel, $container) {
           $container.addClass('pg-no-overflow');
         },

web/pgadmin/static/scss/_pgadmin.style.scss

@@ -264,7 +264,6 @@
 
 .obj_properties {
     padding: 0px;
-    height: 100%;
 }
 
 .obj_properties .pgadmin-control .uneditable-input {