Bump async in /educator-guides/lab-guides/virtual-iot-lab/code/server

Bumps [async](https://github.com/caolan/async) from 2.6.3 to 2.6.4.
- [Release notes](https://github.com/caolan/async/releases)
- [Changelog](https://github.com/caolan/async/blob/v2.6.4/CHANGELOG.md)
- [Commits](https://github.com/caolan/async/compare/v2.6.3...v2.6.4)

---
updated-dependencies:
- dependency-name: async
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <support@github.com>

educator-guides/lab-guides/virtual-iot-lab/code/server/package-lock.json

@@ -14,9 +14,9 @@
       }
     },
     "node_modules/async": {
-            "version": "2.6.3",
-            "resolved": "https://registry.npmjs.org/async/-/async-2.6.3.tgz",
-            "integrity": "sha512-zflvls11DCy+dQWzTW2dzuilv8Z5X/pjfmZOWba6TNIVDm+2UDaJmXSOXlasHKfNBs8oo3M0aT50fDEWfKZjXg==",
+      "version": "2.6.4",
+      "resolved": "https://registry.npmjs.org/async/-/async-2.6.4.tgz",
+      "integrity": "sha512-mzo5dfJYwAn29PeiJ0zvwTo04zj8HDJj0Mn8TD7sno7q12prdbnasKJHhkm2c1LgrhlJ0teaea8860oxi51mGA==",
       "dependencies": {
         "lodash": "^4.17.14"
       }
@@ -127,9 +127,9 @@
       }
     },
     "node_modules/getos/node_modules/async": {
-            "version": "3.2.0",
-            "resolved": "https://registry.npmjs.org/async/-/async-3.2.0.tgz",
-            "integrity": "sha512-TR2mEZFVOj2pLStYxLht7TyfuRzaydfpxr3k9RpHIzMgw7A64dzsdqCxH1WJyQdoe8T10nDXd9wnEigmiuHIZw=="
+      "version": "3.2.3",
+      "resolved": "https://registry.npmjs.org/async/-/async-3.2.3.tgz",
+      "integrity": "sha512-spZRyzKL5l5BZQrr/6m/SqFdBN0q3OCI0f9rjfBzCMBIP4p75P620rR3gTmaksNOhmzgdxcaxdNfMy6anrbM0g=="
     },
     "node_modules/inherits": {
       "version": "2.0.4",
@@ -295,9 +295,9 @@
   },
   "dependencies": {
     "async": {
-            "version": "2.6.3",
-            "resolved": "https://registry.npmjs.org/async/-/async-2.6.3.tgz",
-            "integrity": "sha512-zflvls11DCy+dQWzTW2dzuilv8Z5X/pjfmZOWba6TNIVDm+2UDaJmXSOXlasHKfNBs8oo3M0aT50fDEWfKZjXg==",
+      "version": "2.6.4",
+      "resolved": "https://registry.npmjs.org/async/-/async-2.6.4.tgz",
+      "integrity": "sha512-mzo5dfJYwAn29PeiJ0zvwTo04zj8HDJj0Mn8TD7sno7q12prdbnasKJHhkm2c1LgrhlJ0teaea8860oxi51mGA==",
       "requires": {
         "lodash": "^4.17.14"
       }
@@ -396,9 +396,9 @@
       },
       "dependencies": {
         "async": {
-                    "version": "3.2.0",
-                    "resolved": "https://registry.npmjs.org/async/-/async-3.2.0.tgz",
-                    "integrity": "sha512-TR2mEZFVOj2pLStYxLht7TyfuRzaydfpxr3k9RpHIzMgw7A64dzsdqCxH1WJyQdoe8T10nDXd9wnEigmiuHIZw=="
+          "version": "3.2.3",
+          "resolved": "https://registry.npmjs.org/async/-/async-3.2.3.tgz",
+          "integrity": "sha512-spZRyzKL5l5BZQrr/6m/SqFdBN0q3OCI0f9rjfBzCMBIP4p75P620rR3gTmaksNOhmzgdxcaxdNfMy6anrbM0g=="
         }
       }
     },