Refactor reset of `@uri_string` and `@hash`
Refactor reset of `@uri_string` and `@hash`

These instance variables are reset in a few different places, so I moved
that procedure into a private method to reduce duplication.

EiNSTeiN-/addressable,shaicoleman/addressable,Hacker0x01/addressable,iainbeeston/addressable,sferik/addressable,davidbegin/addressable,sporkmonger/addressable