Docs, fix lint

docs/config.md

@@ -1243,7 +1243,9 @@ and [here](https://easyengine.io/tutorials/nginx/block-wp-login-php-bruteforce-a
     maxretry = 10
     ```
 
-!!! info If you run nginx in a container, append `, chain=DOCKER-USER` to the jail.local action.
+Note that if you run nginx in a container, append `, chain=DOCKER-USER` to the jail.local action. By default, the jail action chain
+is `INPUT`, but `FORWARD` is used when using docker networks. `DOCKER-USER`, available when using docker, is part of the `FORWARD`
+chain.
 
 ## Health checks
 A preliminary health check API endpoint is exposed at `/v1/health`. The endpoint returns a `json` response in the format shown below.

docs/releases.md

@@ -1385,10 +1385,11 @@ and the [ntfy Android app](https://github.com/binwiederhier/ntfy-android/release
 
 **Documentation:**
 
-* Various docs updates ([](https://github.com/binwiederhier/ntfy/pull/1161), thanks to [@OneWeekNotice](https://github.com/OneWeekNotice))
+* Various docs updates ([#1161](https://github.com/binwiederhier/ntfy/pull/1161), thanks to [@OneWeekNotice](https://github.com/OneWeekNotice))
 * Typo in config docs ([#1177](https://github.com/binwiederhier/ntfy/pull/1177), thanks to [@hoho4190](https://github.com/hoho4190))
 * Typo in CLI docs ([#1172](https://github.com/binwiederhier/ntfy/pull/1172), thanks to [@anirvan](https://github.com/anirvan))
-* Correction about MacroDroid ([](https://github.com/binwiederhier/ntfy/pull/1137), thanks to [@ShlomoCode](https://github.com/ShlomoCode))
+* Correction about MacroDroid ([#1137](https://github.com/binwiederhier/ntfy/pull/1137), thanks to [@ShlomoCode](https://github.com/ShlomoCode))
+* Note about fail2ban in Docker ([#1175](https://github.com/binwiederhier/ntfy/pull/1175)), thanks to [@Measurity](https://github.com/Measurity))
 
 ### ntfy Android app v1.16.1 (UNRELEASED)
 

server/server.go

@@ -1828,7 +1828,7 @@ func (s *Server) transformBodyJSON(next handleFunc) handleFunc {
 		if m.Priority != 0 {
 			r.Header.Set("X-Priority", fmt.Sprintf("%d", m.Priority))
 		}
-		if m.Tags != nil && len(m.Tags) > 0 {
+		if len(m.Tags) > 0 {
 			r.Header.Set("X-Tags", strings.Join(m.Tags, ","))
 		}
 		if m.Attach != "" {