message: Fix 'argument to reversed() must be a sequence'
  When passing empty/null location data out of certain rows in the spatial
  control, Superset raises an error when trying to reverse the tuple.
diff: @@ -1852,7 +1852,10 @@ class BaseDeckGLViz(BaseViz):
  elif spatial.get('type') == 'delimited':
  df[key] = (df[spatial.get('lonlatCol')].str.split(spatial.get('delimiter')))
  if spatial.get('reverseCheckbox'):
  - df[key] = [list(reversed(item))for item in df[key]]
  + df[key] = [
  + tuple(reversed(o)) if isinstance(o, (list, tuple)) else (0, 0)
  + for o in df[key]
  + ]
  del df[spatial.get('lonlatCol')]
  elif spatial.get('type') == 'geohash':
  latlong = df[spatial.get('geohashCol')].map(geohash.decode)
  