Cleanup https support code snippet (#8370)

Author: 8ctopus

docs/content/doc/usage/https-support.md

@@ -24,11 +24,11 @@ To use Gitea's built-in HTTPS support, you must change your `app.ini` file:
 
 ```ini
 [server]
-PROTOCOL=https
-ROOT_URL = `https://git.example.com:3000/`
+PROTOCOL  = https
+ROOT_URL  = https://git.example.com:3000/
 HTTP_PORT = 3000
 CERT_FILE = cert.pem
-KEY_FILE = key.pem
+KEY_FILE  = key.pem
 ```
 
 To learn more about the config values, please checkout the [Config Cheat Sheet](../config-cheat-sheet#server).