fix ordering problem in test

Author: Mia-Cross

internal/services/instance/image_test.go

@@ -130,15 +130,15 @@ func TestAccImage_ExternalBlockVolume(t *testing.T) {
 			{
 				Config: `
 					resource "scaleway_block_volume" "main" {
-						size_in_gb = 50
+						size_in_gb = 20
 						iops = 5000
 					}
 					resource "scaleway_block_volume" "additional1" {
-						size_in_gb = 50
-						iops = 5000
+						size_in_gb = 20
+						iops = 15000
 					}
 					resource "scaleway_block_volume" "additional2" {
-						size_in_gb = 50
+						size_in_gb = 40
 						iops = 5000
 					}
 
@@ -173,15 +173,15 @@ func TestAccImage_ExternalBlockVolume(t *testing.T) {
 			{
 				Config: `
 					resource "scaleway_block_volume" "main" {
-						size_in_gb = 50
+						size_in_gb = 20
 						iops = 5000
 					}
 					resource "scaleway_block_volume" "additional1" {
-						size_in_gb = 50
-						iops = 5000
+						size_in_gb = 20
+						iops = 15000
 					}
 					resource "scaleway_block_volume" "additional2" {
-						size_in_gb = 50
+						size_in_gb = 40
 						iops = 5000
 					}