Bump nginx from 35e3238 to b9e1705 in /docker-nginx

Bumps nginx from `35e3238` to `b9e1705`.

---
updated-dependencies:
- dependency-name: nginx
  dependency-type: direct:production
...

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

Author: dependabot[bot]

docker-nginx/Dockerfile

@@ -1,4 +1,4 @@
 # This wraps the upstream nginx image so dependabot can watch it for changes.
 # If https://github.com/dependabot/dependabot-core/issues/390 is addressed, we
 # can just inline this into docker-compose.yml
-FROM nginx:stable-alpine@sha256:35e3238f2f0925a505d5d697df9a9148db9a0c78e89fd2e253919047b3cec824
+FROM nginx:stable-alpine@sha256:b9e1705b69f778dca93cbbbe97d2c2562fb26cac1079cdea4e40d1dad98f14fe