Fix test

pkg/migrator_test.go

@@ -61,7 +61,7 @@ var migrateAcrossVersionsTestCases = []struct {
 		currentVersion:              1,
 		versionTo:                   ptr(4),
 		includeMigrationsToVersions: []int{},
-		expected:                    version1Config,
+		expected:                    nilConfig,
 	},
 }
 
@@ -112,6 +112,8 @@ var migrationData = map[int]map[string]interface{}{
 	4: version4Migration,
 }
 
+var nilConfig = map[string]interface{}(nil)
+
 var version1Config = map[string]interface{}{
 	"agent": map[interface{}]interface{}{
 		"targetEnvironment": "test",