Fix typo causing error in IS_LIST_OF.formatter

[robinvandernoord]

There was a typo in IS_LIST_OF.formatter where it referenced self.other.fomatter (without 'r').
This caused for example the following error on a 'details' view within a py4web grid:

 File "/opt/venv/lib/python3.13/site-packages/py4web/utils/grid.py", line 734, in process
    self.form = Form(
                ~~~~^
        table,
        ^^^^^^
    ...<6 lines>...
        **attrs,
        ^^^^^^^^
    )
    ^
  File "/opt/venv/lib/python3.13/site-packages/py4web/utils/form.py", line 767, in __init__
    self.vars = self._read_vars_from_record(table)
                ~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^
  File "/opt/venv/lib/python3.13/site-packages/py4web/utils/form.py", line 868, in _read_vars_from_record
    name: table[name].formatter(self.record[name])
          ~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^
  File "/opt/venv/lib/python3.13/site-packages/pydal/objects.py", line 2449, in formatter
    value = item.formatter(value)
  File "/opt/venv/lib/python3.13/site-packages/pydal/validators.py", line 4123, in formatter
    return ", ".join(map(quote_token, map(self.other.fomatter, value)))
                                          ^^^^^^^^^^^^^^^^^^^
AttributeError: 'IS_EMPTY_OR' object has no attribute 'fomatter'. Did you mean: 'formatter'?