[MM-61775] Fix errcheck issues in server/channels/app/platform/web_broadcast_hook.go (#29514)

Co-authored-by: Caleb Roseland <caleb@calebroseland.com>

server/.golangci.yml

@@ -95,7 +95,6 @@ issues:
         channels/app/platform/license.go|\
         channels/app/platform/session.go|\
         channels/app/platform/status.go|\
-        channels/app/platform/web_broadcast_hook.go|\
         channels/app/platform/web_hub_test.go|\
         channels/app/plugin_test.go|\
         channels/app/post_helpers_test.go|\