Fix CI (#1010)

* replace docker image with newer version (tested locally, `curl` and `apksigner` are available)
* update the container before signing. This is necessary because `curl` is outdated, but can be updated via `apt` (tested locally, working **only** after update)

I hope this way is fine, I don't really anything about docker and just tried to fix it :)

Co-authored-by: qwerty287 <ndev@web.de>
Reviewed-on: https://codeberg.org/gitnex/GitNex/pulls/1010
Reviewed-by: M M Arif <mmarif@noreply.codeberg.org>
Co-authored-by: qwerty287 <qwerty287@noreply.codeberg.org>
Co-committed-by: qwerty287 <qwerty287@noreply.codeberg.org>

.gitlab-ci.yml

@@ -30,7 +30,7 @@ build:
     expire_in: 15 minutes
 
 sign:
-  image: nextcloudci/android:android-54
+  image: nextcloudci/android8:android-61
   stage: sign
   only:
     - main

scripts/sign-build.sh

@@ -9,6 +9,10 @@
 [ -z "${KS_FILE}" ] && { echo "Filename of keystore is missing (KS_FILE)"; exit 1; }
 [ -z "${OUTPUT}" ] && { echo "Missing filename of signed output (OUTPUT)"; exit 1; }
 
+# Update the docker container. curl is an outdated version which has to be updated.
+apt update
+apt upgrade curl
+
 KEYFILE=$(mktemp)
 curl -X GET "${INSTANCE}/api/v1/repos/${KS_REPO}/contents/${KS_FILE}?token=${BOT_TOKEN}" -H  "accept: application/json" | sed 's|"content":"|#|g' | cut -d '#' -f 2 | cut -d '"' -f 1 | base64 -d > ${KEYFILE}