provisioning: simplify db query

the GetProvisionedDashboardQuery wasent used for anything
else than check if a dashboard is provisioned or not. So
we simplified this query to make it more maintainable.

pkg/models/dashboards.go

@@ -33,8 +33,8 @@ var (
 	ErrDashboardInvalidUid                     = errors.New("uid contains illegal characters")
 	ErrDashboardUidToLong                      = errors.New("uid to long. max 40 characters")
 	ErrDashboardCannotSaveProvisionedDashboard = errors.New("Cannot save provisioned dashboard")
-	ErrDashboardProvisioningDoesNotExist       = errors.New("Dashboard provisioning does not exist")
-	RootFolderName                             = "General"
+	//ErrDashboardProvisioningDoesNotExist       = errors.New("Dashboard provisioning does not exist")
+	RootFolderName = "General"
 )
 
 type UpdatePluginDashboardError struct {
@@ -319,10 +319,10 @@ type GetDashboardSlugByIdQuery struct {
 	Result string
 }
 
-type GetProvisionedDashboardByDashboardId struct {
+type IsDashboardProvisionedQuery struct {
 	DashboardId int64
 
-	Result *DashboardProvisioning
+	Result bool
 }
 
 type GetProvisionedDashboardDataQuery struct {