CLOUDP-321083: fix reconciliation loop on dbuser

In 140ba21 I added the ability to set a
description on AtlasDatabaseUser. However, I overlooked that a
description could already exist on the user in Atlas, in which case the
operator will fetch it, realize it's different, and then... omit the
change, because `omitempty` is set on the struct field.

With this patch we send an empty string instead.

Author: tvdw-mongodb

internal/translation/dbuser/conversion.go

@@ -156,7 +156,7 @@ func toAtlas(au *User) (*admin.CloudDatabaseUser, error) {
 		X509Type:        pointer.MakePtrOrNil(au.X509Type),
 		AwsIAMType:      pointer.MakePtrOrNil(au.AWSIAMType),
 		GroupId:         au.ProjectID,
-		Description:     pointer.MakePtrOrNil(au.Description),
+		Description:     pointer.MakePtr(au.Description),
 		Labels:          labelsToAtlas(au.Labels),
 		Roles:           rolesToAtlas(au.Roles),
 		Scopes:          scopesToAtlas(au.Scopes),