build: niv advisory-db: update 6a422853 -> fe7b79e8 (#2713)

## Changelog for advisory-db:
Branch: main
Commits: [rustsec/advisory-db@6a422853...fe7b79e8](rustsec/advisory-db@6a42285...fe7b79e)

* [`e40084b1`](rustsec/advisory-db@e40084b) Add advisory for logging of access tokens in matrix-sdk ([RustSec/advisory-db⁠#1444](http://r.duckduckgo.com/l/?uddg=https://github.com/RustSec/advisory-db/issues/1444))
* [`fe7b79e8`](rustsec/advisory-db@fe7b79e) Assigned RUSTSEC-2022-0062 to matrix-sdk ([RustSec/advisory-db⁠#1445](http://r.duckduckgo.com/l/?uddg=https://github.com/RustSec/advisory-db/issues/1445))

nix/sources.json

@@ -6,10 +6,10 @@
         "homepage": "https://rustsec.org",
         "owner": "RustSec",
         "repo": "advisory-db",
-        "rev": "6a422853c07d95546b7c683d5ae4d7d54a2b30a6",
-        "sha256": "1ysf04kckafp0rm8w3y9nim2i8x5n087hds5fh6lr86f0sbl3d40",
+        "rev": "fe7b79e8ebf9ad03660e573e0c2a1ed4e80dee5d",
+        "sha256": "0p1xr0fpgqrji6ma7axi5p2l455vc1rhcr2wx62k3spjwmyqxnbd",
         "type": "tarball",
-        "url": "https://github.com/RustSec/advisory-db/archive/6a422853c07d95546b7c683d5ae4d7d54a2b30a6.tar.gz",
+        "url": "https://github.com/RustSec/advisory-db/archive/fe7b79e8ebf9ad03660e573e0c2a1ed4e80dee5d.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     },
     "canister-sandbox-x86_64-darwin": {