Fix JWT Bearer security JSON sample

As reported by @pjmolina [here](Mermade/oas-kit#2)

Author: MikeRalphson

versions/3.0.md

@@ -3306,7 +3306,7 @@ in: header
 
 ```json
 {
-  "type": "scheme",
+  "type": "http",
   "scheme": "bearer",
   "bearerFormat": "JWT",
 }