Bump github.com/gorilla/websocket from 1.4.0 to 1.4.1 in /demo/chat

Bumps [github.com/gorilla/websocket](https://github.com/gorilla/websocket) from 1.4.0 to 1.4.1.
- [Release notes](https://github.com/gorilla/websocket/releases)
- [Commits](gorilla/websocket@v1.4.0...v1.4.1)

---
updated-dependencies:
- dependency-name: github.com/gorilla/websocket
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

demo/chat/go.mod

@@ -2,4 +2,4 @@ module chat
 
 go 1.12
 
-require github.com/gorilla/websocket v1.4.0
+require github.com/gorilla/websocket v1.4.1

demo/chat/go.sum

@@ -1,2 +1,2 @@
-github.com/gorilla/websocket v1.4.0 h1:WDFjx/TMzVgy9VdMMQi2K2Emtwi2QcUQsztZ/zLaH/Q=
-github.com/gorilla/websocket v1.4.0/go.mod h1:E7qHFY5m1UJ88s3WnNqhKjPHQ0heANvMoAMk2YaljkQ=
+github.com/gorilla/websocket v1.4.1 h1:q7AeDBpnBk8AogcD4DSag/Ukw/KV+YhzLj2bP5HvKCM=
+github.com/gorilla/websocket v1.4.1/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=