chore: add 9714's changelog

changes/v5.0.14/fix-9714.en.md

@@ -0,0 +1 @@
+Fix `/mqtt/auto_subscribe` API's bad swagger schema, and make sure swagger always checks if the schema is correct.

changes/v5.0.14/fix-9714.zh.md

@@ -0,0 +1 @@
+修复 `/mqtt/auto_subscribe` API 错误的 swagger 格式，并且保证 swagger 总是检查格式是否正确。