Update MIGRATION.md
Minor edit
routes defined with trailing slashes will become inaccessible when
using `NormalizePath::default()`.
- Before: `#[get("/test/")`
- After: `#[get("/test")`
+ Before: `#[get("/test/")]`
+ After: `#[get("/test")]`
Alternatively, explicitly require trailing slashes: `NormalizePath::new(TrailingSlash::Always)`.
