[dashboard] downgrade Caddy

because of issues with 308 responsed on static assests.

Author: AlexTugarev

Diff for: components/dashboard/leeway.Dockerfile

@@ -18,7 +18,7 @@ RUN find . -type f \( -name '*.html' -o -name '*.js' -o -name '*.css' -o -name '
 
 COPY components-gitpod-protocol--gitpod-schema/gitpod-schema.json /www/static/schemas/gitpod-schema.json
 
-FROM caddy/caddy:2.6.2-alpine
+FROM caddy/caddy:2.4.0-alpine
 
 COPY components-dashboard--static/conf/Caddyfile /etc/caddy/Caddyfile
 COPY --from=compress /www /www