Converting to structured logging the file api4/websocket.go (#12118)

api4/websocket.go

@@ -4,7 +4,6 @@
 package api4
 
 import (
-	"fmt"
 	"net/http"
 
 	"github.com/gorilla/websocket"
@@ -25,7 +24,7 @@ func connectWebSocket(c *Context, w http.ResponseWriter, r *http.Request) {
 
 	ws, err := upgrader.Upgrade(w, r, nil)
 	if err != nil {
-		mlog.Error(fmt.Sprintf("websocket connect err: %v", err))
+		mlog.Error("websocket connect err.", mlog.Err(err))
 		c.Err = model.NewAppError("connect", "api.web_socket.connect.upgrade.app_error", nil, "", http.StatusInternalServerError)
 		return
 	}