Fix megacheck issue unused code.

I removed some code, and commented out other one.

See,
$ gometalinter --vendor --disable-all --disable=gotype --enable=megacheck --deadline 6m ./... | grep unused
pkg/api/avatar/avatar.go:100:26⚠️ func (*CacheServer).mustInt is unused (U1000) (megacheck)
pkg/api/folder_test.go:136:6⚠️ func callGetFolderByUID is unused (U1000) (megacheck)
pkg/api/folder_test.go:141:6⚠️ func callDeleteFolder is unused (U1000) (megacheck)
pkg/api/live/hub.go:40:15⚠️ func (*hub).removeConnection is unused (U1000) (megacheck)
pkg/components/imguploader/azureblobuploader.go:130:5⚠️ var client is unused (U1000) (megacheck)
pkg/middleware/middleware_test.go:438:28⚠️ func (*scenarioContext).withInvalidApiKey is unused (U1000) (megacheck)
pkg/services/alerting/ticker.go:40:18⚠️ func (*Ticker).updateOffset is unused (U1000) (megacheck)
pkg/services/notifications/notifications_test.go:12:6⚠️ type testTriggeredAlert is unused (U1000) (megacheck)
pkg/services/sqlstore/dashboard_service_integration_test.go:935:6⚠️ type scenarioContext is unused (U1000) (megacheck)
pkg/services/sqlstore/dashboard_service_integration_test.go:939:6⚠️ type scenarioFunc is unused (U1000) (megacheck)
pkg/services/sqlstore/dashboard_service_integration_test.go:941:6⚠️ func dashboardGuardianScenario is unused (U1000) (megacheck)
pkg/services/sqlstore/transactions_test.go:13:6⚠️ type testQuery is unused (U1000) (megacheck)

pkg/services/sqlstore/dashboard_service_integration_test.go

@@ -932,29 +932,6 @@ func TestIntegratedDashboardService(t *testing.T) {
 	})
 }
 
-type scenarioContext struct {
-	dashboardGuardianMock *guardian.FakeDashboardGuardian
-}
-
-type scenarioFunc func(c *scenarioContext)
-
-func dashboardGuardianScenario(desc string, mock *guardian.FakeDashboardGuardian, fn scenarioFunc) {
-	Convey(desc, func() {
-		origNewDashboardGuardian := guardian.New
-		guardian.MockDashboardGuardian(mock)
-
-		sc := &scenarioContext{
-			dashboardGuardianMock: mock,
-		}
-
-		defer func() {
-			guardian.New = origNewDashboardGuardian
-		}()
-
-		fn(sc)
-	})
-}
-
 type dashboardPermissionScenarioContext struct {
 	dashboardGuardianMock *guardian.FakeDashboardGuardian
 }

pkg/services/sqlstore/transactions_test.go

@@ -10,10 +10,6 @@ import (
 	. "github.com/smartystreets/goconvey/convey"
 )
 
-type testQuery struct {
-	result bool
-}
-
 var ProvokedError = errors.New("testing error.")
 
 func TestTransaction(t *testing.T) {