URL argument handler does not allow multiple values

The field's argument handler is currently set to SearchApiViewsHandlerArgument since the $inner_type value is uri, not string. This results in the multiple arguments being split up by views_break_phrase(), which only allows numeric arguments:

  if ($inner_type == 'string') {
    $table[$id]['argument']['handler'] = 'SearchApiViewsHandlerArgumentString';
  }
  else {
    $table[$id]['argument']['handler'] = 'SearchApiViewsHandlerArgument';
  }

Adding the uri type to the string conditional registers the correct argument handler, which uses views_break_phrase_string() to properly handle multiple arguments.

Patch attached below.