`Dyn::string` assumes default reader `R`

[Dyn::string](https://docs.rs/object/0.37.3/object/read/elf/trait.Dyn.html#method.string) receives the `strings` parameter as `StringTable<'data>`, assuming default parameter for `R`. However if I have a `StringTable<'data, R = SomeNonDefaultReader>` it is impossible to call `string`, although it should work for any reader.