Recommend upgrading treq alongside twisted (#11943)

Author: babolivier

CHANGES.md

@@ -7,7 +7,7 @@ Note that [Twisted 22.1.0](https://github.com/twisted/twisted/releases/tag/twist
 has recently been released, which fixes a [security issue](https://github.com/twisted/twisted/security/advisories/GHSA-92x2-jw7w-xvvx)
 within the Twisted library. We do not believe Synapse is affected by this vulnerability,
 though we advise server administrators who installed Synapse via pip to upgrade Twisted
-with `pip install --upgrade Twisted` as a matter of good practice. The Docker image
+with `pip install --upgrade Twisted treq` as a matter of good practice. The Docker image
 `matrixdotorg/synapse` and the Debian packages from `packages.matrix.org` are using the
 updated library.
 

docs/upgrade.md

@@ -93,7 +93,7 @@ Note that [Twisted 22.1.0](https://github.com/twisted/twisted/releases/tag/twist
 has recently been released, which fixes a [security issue](https://github.com/twisted/twisted/security/advisories/GHSA-92x2-jw7w-xvvx)
 within the Twisted library. We do not believe Synapse is affected by this vulnerability,
 though we advise server administrators who installed Synapse via pip to upgrade Twisted
-with `pip install --upgrade Twisted` as a matter of good practice. The Docker image
+with `pip install --upgrade Twisted treq` as a matter of good practice. The Docker image
 `matrixdotorg/synapse` and the Debian packages from `packages.matrix.org` are using the
 updated library.