dockerfile issue

**Describe the bug**
Dockerfile:1
--------------------
1 | >>> FROM java:8
2 |
3 | WORKDIR /superglue/backend
--------------------
ERROR: failed to solve: java:8: docker.io/library/java:8: not found

Update code to "FROM openjdk:8"

**To Reproduce**
run docker-compose command

**Expected behavior**
the command runs successfully

**Desktop (please complete the following information):**
- OS: MacOS

Open the Dockerfile and inspect line 1, where the build uses java:8. Run the docker-compose command to reproduce the missing-image error, update the base image reference, and confirm that the command runs successfully.

Written by the indexing model from the issue text.