tcp accept should retry when encoutering some kinds of error (#565)

* tcp accept should retry when encoutering some kinds of error

bump version to v2.1.2

* persistent temporary machine id

.github/workflows/release.yml

@@ -21,7 +21,7 @@ on:
       version:
         description: 'Version for this release'
         type: string
-        default: 'v2.1.1'
+        default: 'v2.1.2'
         required: true
       make_latest:
         description: 'Mark this release as latest'