tech(tsdb): remove skip ssl setting. should be based on datasource settings

pkg/setting/setting.go

@@ -141,8 +141,7 @@ var (
 	Quota QuotaSettings
 
 	// Alerting
-	AlertingEnabled           bool
-	AlertingSkipSSLValidation bool
+	AlertingEnabled bool
 
 	// logger
 	logger log.Logger

pkg/tsdb/graphite/graphite.go

@@ -34,7 +34,7 @@ func init() {
 	tsdb.RegisterExecutor("graphite", NewGraphiteExecutor)
 
 	tr := &http.Transport{
-		TLSClientConfig: &tls.Config{InsecureSkipVerify: setting.AlertingSkipSSLValidation},
+		TLSClientConfig: &tls.Config{InsecureSkipVerify: true},
 	}
 
 	HttpClient = http.Client{