[MM-41671] Support Email Position+Validation (#19590)

api4/config.go

@@ -147,8 +147,7 @@ func updateConfig(c *Context, w http.ResponseWriter, r *http.Request) {
 
 	c.App.HandleMessageExportConfig(cfg, appCfg)
 
-	err := cfg.IsValid()
+	if err := cfg.IsValid(); err != nil {
-	if err != nil {
 		c.Err = err
 		return
 	}

model/config.go

@@ -1739,7 +1739,7 @@ type SupportSettings struct {
 	AboutLink                              *string `access:"site_customization,write_restrictable,cloud_restrictable"`
 	HelpLink                               *string `access:"site_customization,write_restrictable,cloud_restrictable"`
 	ReportAProblemLink                     *string `access:"site_customization,write_restrictable,cloud_restrictable"`
-	SupportEmail                           *string `access:"site_customization"`
+	SupportEmail                           *string `access:"site_notifications"`
 	CustomTermsOfServiceEnabled            *bool   `access:"compliance_custom_terms_of_service"`
 	CustomTermsOfServiceReAcceptancePeriod *int    `access:"compliance_custom_terms_of_service"`
 	EnableAskCommunityLink                 *bool   `access:"site_customization"`