Fix README typo

Follows PR review.

Follows up #224

Author: DifferentialOrange

README.md

@@ -733,7 +733,7 @@ with `{ operation = 'select', name = space_name }` labels.
 Statistics are preserved between package reloads or [Tarantool Cartridge
 role reloads](https://www.tarantool.io/en/doc/latest/book/cartridge/cartridge_api/modules/cartridge.roles/#reload).
 Beware that metrics 0.12.0 and below do not support
-preverving stats between role reload
+preserving stats between role reload
 (see [tarantool/metrics#334](https://github.com/tarantool/metrics/issues/334)),
 thus this feature will be unsupported for `metrics` driver.