fix(Xapi#exportDeltaVm): make streams property non-enumerable

src/xapi.js

@@ -1373,10 +1373,7 @@ export default class Xapi extends XapiBase {
       vifs[vif.$ref] = vif
     })
 
-    return {
-      // TODO: make non-enumerable?
-      streams: await streams::pAll(),
-
+    return Object.defineProperty({
       version: '1.0.0',
       vbds,
       vdis,
@@ -1390,7 +1387,9 @@ export default class Xapi extends XapiBase {
           }
         }
         : vm
-    }
+    }, 'streams', {
+      value: await streams::pAll()
+    })
   }
 
   @deferrable.onFailure

src/xo-mixins/backups.js

@@ -545,12 +545,8 @@ export default class {
 
     $onFailure(() => handler.unlink(infoPath)::pCatch(noop))
 
-    const {
-      ...infos
-    } = delta
-
     // Write Metadata.
-    await handler.outputFile(infoPath, JSON.stringify(infos, null, 2), {flag: 'wx'})
+    await handler.outputFile(infoPath, JSON.stringify(delta, null, 2), {flag: 'wx'})
 
     // Here we have a completed backup. We can merge old vdis.
     await Promise.all(