methods: fix the option_unwrap_used message
methods: fix the option_unwrap_used message

It had a hard linewrap in it rather than flowing naturally. This
confused the Vim error matching.

graydon/rust,aidancully/rust,graydon/rust,graydon/rust,aidancully/rust,graydon/rust,aidancully/rust,graydon/rust,aidancully/rust,aidancully/rust,aidancully/rust,graydon/rust