(changelog): Fix typo
## [1.25.0] - UNRELEASED
This version of Rustup involves a significant number of internal cleanups, both in terms
-of the Rutup code and its documentation. In addition to a lot of work on the codebase
+of the Rustup code and its documentation. In addition to a lot of work on the codebase
itself, due to the length of time since the last release this one has a record number
of contributors and we thank you all for your efforts and time.
