build: niv advisory-db: update fe5f044f -> 68ccfc5b

## Changelog for advisory-db:
Branch: master
Commits: [rustsec/advisory-db@fe5f044f...68ccfc5b](rustsec/advisory-db@fe5f044...68ccfc5)

* [`aced392f`](rustsec/advisory-db@aced392) Add unmaintained advisory for rulinalg crate
* [`25e792c0`](rustsec/advisory-db@25e792c) Add unmaintained advisory for office crate. Fixes [RustSec/advisory-db⁠#742](http://r.duckduckgo.com/l/?uddg=https://github.com/RustSec/advisory-db/issues/742)
* [`240080a1`](rustsec/advisory-db@240080a) Assigned RUSTSEC-2021-0034 to office
* [`a0ec5819`](rustsec/advisory-db@a0ec581) Add advisory for invalid layout assumptions in quinn ([RustSec/advisory-db⁠#804](http://r.duckduckgo.com/l/?uddg=https://github.com/RustSec/advisory-db/issues/804))
* [`e93938cb`](rustsec/advisory-db@e93938c) Assigned RUSTSEC-2021-0035 to quinn ([RustSec/advisory-db⁠#805](http://r.duckduckgo.com/l/?uddg=https://github.com/RustSec/advisory-db/issues/805))
* [`0f0dbd06`](rustsec/advisory-db@0f0dbd0) Assigned RUSTSEC-2020-0147 to rulinalg
* [`ac5a6f92`](rustsec/advisory-db@ac5a6f9) Report 0162-internment to RustSec
* [`423ca504`](rustsec/advisory-db@423ca50) Assigned RUSTSEC-2021-0036 to internment

Author: dfinity-bot

nix/sources.json

@@ -6,10 +6,10 @@
         "homepage": "https://rustsec.org",
         "owner": "RustSec",
         "repo": "advisory-db",
-        "rev": "fe5f044f5c0a26082aa9ff216a4be46a2a5efcb4",
-        "sha256": "0mmnz1qgi6n87f0f3g85w12apdgxxrr44w31pr25ax6d28gmcc1m",
+        "rev": "68ccfc5bab9fcc5dca483ac19095cf5c794dc874",
+        "sha256": "0s4m1v7fc4b8svzcw4vy6g38bc1q7sfkd3gw0vyxxj9kfbsfbpcf",
         "type": "tarball",
-        "url": "https://github.com/RustSec/advisory-db/archive/fe5f044f5c0a26082aa9ff216a4be46a2a5efcb4.tar.gz",
+        "url": "https://github.com/RustSec/advisory-db/archive/68ccfc5bab9fcc5dca483ac19095cf5c794dc874.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     },
     "agent-js-monorepo": {