message: fix missing vars
diff: var pdbProvider = getParam('pdb-provider', '[^&]+').trim().toLowerCase();
  var emdbProvider = getParam('emdb-provider', '[^&]+').trim().toLowerCase();
  var viewer = new molstar.Viewer('app', {
  - disableAntialiasing: disableAntialiasing,
  - pixelScale: pixelScale,
  - enableWboit: !disableWboit,
  layoutShowControls: !hideControls,
  viewportShowExpand: false,
  pdbProvider: pdbProvider || 'pdbe',
  