chore(deps): update container image cthulhoo/ttrss-web-nginx to latest@351c9ef by renovate (#24742)

This PR contains the following updates:

| Package | Update | Change |
|---|---|---|
| cthulhoo/ttrss-web-nginx | digest | `822af36` -> `351c9ef` |

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This PR has been generated by [Renovate
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<!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiIzOC4xOC4xMiIsInVwZGF0ZWRJblZlciI6IjM4LjE4LjEyIiwidGFyZ2V0QnJhbmNoIjoibWFzdGVyIiwibGFiZWxzIjpbImF1dG9tZXJnZSIsInVwZGF0ZS9kb2NrZXIvZ2VuZXJhbC9ub24tbWFqb3IiXX0=-->

charts/stable/tt-rss/Chart.yaml

@@ -34,4 +34,4 @@ sources:
   - https://hub.docker.com/r/cthulhoo/ttrss-fpm-pgsql-static
   - https://hub.docker.com/r/cthulhoo/ttrss-web-nginx
 type: application
-version: 18.1.20
+version: 18.1.21

charts/stable/tt-rss/values.yaml

@@ -5,7 +5,7 @@ image:
 nginxImage:
   repository: cthulhoo/ttrss-web-nginx
   pullPolicy: IfNotPresent
-  tag: latest@sha256:822af36bc401f049c5a13c78c452b554fe569d46a16f3e0168b37ccb3acffa33
+  tag: latest@sha256:351c9ef9f491b68e42bc6da654efcc65bc278330b95c478807a7aae26882a86f
 updaterImage:
   repository: cthulhoo/ttrss-fpm-pgsql-static
   pullPolicy: IfNotPresent