[MM-31360] downgrade error logs which doesn't break the flow (#16612)

* downgrade error logs which doesn't break the flow

* reflect revivew comments

api4/channel.go

@@ -212,7 +212,7 @@ func updateChannel(c *Context, w http.ResponseWriter, r *http.Request) {
 
 	if oldChannelDisplayName != channel.DisplayName {
 		if err := c.App.PostUpdateChannelDisplayNameMessage(c.App.Session().UserId, channel, oldChannelDisplayName, channel.DisplayName); err != nil {
-			mlog.Error(err.Error())
+			mlog.Warn("Error while posting channel display name message", mlog.Err(err))
 		}
 	}
 

api4/system.go

@@ -361,7 +361,7 @@ func getSupportedTimezones(c *Context, w http.ResponseWriter, r *http.Request) {
 
 	b, err := json.Marshal(supportedTimezones)
 	if err != nil {
-		c.Log.Warn("Unable to marshal JSON in timezones.", mlog.Err(err))
+		c.Logger.Warn("Unable to marshal JSON in timezones.", mlog.Err(err))
 		w.WriteHeader(http.StatusInternalServerError)
 	}
 

api4/user.go

@@ -167,7 +167,7 @@ func createUser(c *Context, w http.ResponseWriter, r *http.Request) {
 	if ruser != nil {
 		err = c.App.CheckAndSendUserLimitWarningEmails()
 		if err != nil {
-			mlog.Error(err.Error())
+			c.LogErrorByCode(err)
 		}
 	}
 
@@ -1358,7 +1358,7 @@ func updateUserActive(c *Context, w http.ResponseWriter, r *http.Request) {
 	if isSelfDeactive {
 		c.App.Srv().Go(func() {
 			if err = c.App.Srv().EmailService.SendDeactivateAccountEmail(user.Email, user.Locale, c.App.GetSiteURL()); err != nil {
-				mlog.Error(err.Error())
+				c.LogErrorByCode(err)
 			}
 		})
 	}
@@ -1823,7 +1823,7 @@ func loginCWS(c *Context, w http.ResponseWriter, r *http.Request) {
 	user, err := c.App.AuthenticateUserForLogin("", loginID, "", "", token, false)
 	if err != nil {
 		c.LogAuditWithUserId("", "failure - login_id="+loginID)
-		mlog.Error("CWS authentication error", mlog.Err(err))
+		c.LogErrorByCode(err)
 		http.Redirect(w, r, *c.App.Config().ServiceSettings.SiteURL, 302)
 		return
 	}
@@ -1831,7 +1831,7 @@ func loginCWS(c *Context, w http.ResponseWriter, r *http.Request) {
 	c.LogAuditWithUserId(user.Id, "authenticated")
 	err = c.App.DoLogin(w, r, user, "", false, false, false)
 	if err != nil {
-		mlog.Error("CWS login error", mlog.Err(err))
+		c.LogErrorByCode(err)
 		http.Redirect(w, r, *c.App.Config().ServiceSettings.SiteURL, 302)
 		return
 	}
@@ -2110,7 +2110,7 @@ func sendVerificationEmail(c *Context, w http.ResponseWriter, r *http.Request) {
 
 	if err = c.App.SendEmailVerification(user, user.Email, redirect); err != nil {
 		// Don't want to leak whether the email is valid or not
-		mlog.Error(err.Error())
+		c.LogErrorByCode(err)
 		ReturnStatusOK(w)
 		return
 	}