comment unused struct fields

pkg/services/alerting/engine.go

@@ -16,7 +16,7 @@ import (
 
 type Engine struct {
 	execQueue chan *Job
-	clock         clock.Clock
+	//clock         clock.Clock
 	ticker        *Ticker
 	scheduler     Scheduler
 	evalHandler   EvalHandler

pkg/services/alerting/reader.go

@@ -16,7 +16,7 @@ type RuleReader interface {
 
 type DefaultRuleReader struct {
 	sync.RWMutex
-	serverID       string
+	//serverID       string
 	serverPosition int
 	clusterSize    int
 	log            log.Logger

pkg/services/sqlstore/migrator/migrations.go

@@ -179,7 +179,7 @@ type CopyTableDataMigration struct {
 	targetTable string
 	sourceCols  []string
 	targetCols  []string
-	colMap      map[string]string
+	//colMap      map[string]string
 }
 
 func NewCopyTableDataMigration(targetTable string, sourceTable string, colMap map[string]string) *CopyTableDataMigration {