Reduce utils.Cfg references (#7650)

* app.UpdateConfig method

* test fix

* another test fix

* the config override option as-was is just error prone, remove it for now

* derp

api/context.go

@@ -191,7 +191,7 @@ func (h handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		c.Path = "/" + strings.Join(splitURL[2:], "/")
 	}
 
-	if h.isApi && !*utils.Cfg.ServiceSettings.EnableAPIv3 {
+	if h.isApi && !*c.App.Config().ServiceSettings.EnableAPIv3 {
 		c.Err = model.NewAppError("ServeHTTP", "api.context.v3_disabled.app_error", nil, "", http.StatusNotImplemented)
 	}
 
@@ -229,7 +229,7 @@ func (h handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		c.Err.Where = r.URL.Path
 
 		// Block out detailed error when not in developer mode
-		if !*utils.Cfg.ServiceSettings.EnableDeveloper {
+		if !*c.App.Config().ServiceSettings.EnableDeveloper {
 			c.Err.DetailedError = ""
 		}
 
@@ -294,7 +294,7 @@ func (c *Context) LogDebug(err *model.AppError) {
 }
 
 func (c *Context) UserRequired() {
-	if !*utils.Cfg.ServiceSettings.EnableUserAccessTokens && c.Session.Props[model.SESSION_PROP_TYPE] == model.SESSION_TYPE_USER_ACCESS_TOKEN {
+	if !*c.App.Config().ServiceSettings.EnableUserAccessTokens && c.Session.Props[model.SESSION_PROP_TYPE] == model.SESSION_TYPE_USER_ACCESS_TOKEN {
 		c.Err = model.NewAppError("", "api.context.session_expired.app_error", nil, "UserAccessToken", http.StatusUnauthorized)
 		return
 	}
@@ -307,7 +307,7 @@ func (c *Context) UserRequired() {
 
 func (c *Context) MfaRequired() {
 	// Must be licensed for MFA and have it configured for enforcement
-	if !utils.IsLicensed() || !*utils.License().Features.MFA || !*utils.Cfg.ServiceSettings.EnableMultifactorAuthentication || !*utils.Cfg.ServiceSettings.EnforceMultifactorAuthentication {
+	if !utils.IsLicensed() || !*utils.License().Features.MFA || !*c.App.Config().ServiceSettings.EnableMultifactorAuthentication || !*c.App.Config().ServiceSettings.EnforceMultifactorAuthentication {
 		return
 	}