try imagemagick6

Signed-off-by: Simon L <szaimen@e.mail.de>

Containers/nextcloud/Dockerfile

@@ -47,7 +47,7 @@ RUN set -ex; \
         ghostscript-dev \
         tiff-dev \
         zlib-dev \
-        imagemagick-dev \
+        imagemagick6-dev \
         libheif-dev \
         librsvg-dev \
         libxext-dev \

Containers/nextcloud/start.sh

@@ -43,6 +43,9 @@ if [ -n "$ADDITIONAL_APKS" ]; then
     if ! [ -f "/additional-apks-are-installed" ]; then
         read -ra ADDITIONAL_APKS_ARRAY <<< "$ADDITIONAL_APKS"
         for app in "${ADDITIONAL_APKS_ARRAY[@]}"; do
+            if [ "$app" = "imagemagick" ]; then
+                app=imagemagick6
+            fi
             echo "Installing $app via apk..."
             if ! apk add --no-cache "$app" >/dev/null; then
                 echo "The packet $app was not installed!"