Fix typo in pr link

Author: yinx

CHANGELOG.md

@@ -4,7 +4,7 @@ All notable changes to `laravel-verification-code` will be documented in this fi
 
 ## 0.3.4 - 2020-12-16
 
-- Verifying test verifiables is now case insensitive ([#12](https://github.com/nextapps-be/laravel-verification-code/pull/13))
+- Verifying test verifiables is now case insensitive ([#13](https://github.com/nextapps-be/laravel-verification-code/pull/13))
 
 ## 0.3.3 - 2020-10-23