fix: use nonexistent image for install/upgrade RED canary

Reviewed-on: https://git.coopcloud.tech/coop-cloud/custom-html-tiny/pulls/4

README.md

@@ -23,6 +23,6 @@ Custom HTML website, served using thttpd
 5. `abra app deploy YOURAPPDOMAIN`
 6. Copy your files to the container, using something like
 ```
-abra app YOURAPPDOMAIN cp index.html app:/content
+abra app cp YOURAPPDOMAIN index.html app:/var/www/http
 ```
 

compose.yml

@@ -3,7 +3,7 @@ version: "3.8"
 
 services:
   app:
-    image: joseluisq/static-web-server:2.38.0
+    image: joseluisq/static-web-server:nonexistent-cc-ci-canary-bad
     command:  ["-a", "0.0.0.0", "-p", "80", "-g", "warn", "-d", "/var/www/http/$HTTP_SUBDIR"]
     networks:
       - proxy
@@ -29,4 +29,3 @@ volumes:
 networks:
   proxy:
     external: true
-