Remove references to two unknown lints in config

`option_map_unwrap_or` and `seek_rewind` are not current lints, and
cannot be referenced as having the `msrv` configuration option.

Author: samueltardieu

clippy_config/src/conf.rs

@@ -775,15 +775,13 @@ define_Conf! {
         needless_borrow,
         non_std_lazy_statics,
         option_as_ref_deref,
-        option_map_unwrap_or,
         ptr_as_ptr,
         question_mark,
         redundant_field_names,
         redundant_static_lifetimes,
         repeat_vec_with_capacity,
         same_item_push,
         seek_from_current,
-        seek_rewind,
         to_digit_is_some,
         transmute_ptr_to_ref,
         tuple_array_conversions,