message: Change validator of timeshift to allow for strings
diff: @@ -939,7 +939,6 @@ export const fields = {
  time_compare: {
  type: 'TextField',
  label: 'Time Shift',
  - isInt: true,
  default: null,
  description: 'Overlay a timeseries from a ' +
  'relative time period. Expects relative time delta ' +
  