fix the upload postprocessing when the destination file does not exis…

[2403905]

Fix the upload postprocessing when the destination file does not exist anymore.

Describe the bug

When a file gets deleted before the postprocessing the destination and blob file are not found and BlobID is empty
owncloud/ocis#7909

Steps to reproduce

folder='ff'
file2='ff2.txt'
# get the drive id
driveid=`curl -ku admin:admin https://host.docker.internal:9200/graph/v1.0/me/drives | jq -c '.[] | .[] | select(.driveAlias | contains("personal")) | .id' -r`

# create a folder
curl -ku admin:admin -XMKCOL 'https://host.docker.internal:9200/dav/spaces/'$driveid'/'$folder

# create, delete, and overwrite the same file 
curl -ku admin:admin -XPUT -d"content" 'https://host.docker.internal:9200/dav/spaces/'$driveid'/'$folder'/'$file2
curl -ku admin:admin -XDELETE 'https://host.docker.internal:9200/dav/spaces/'$driveid'/'$folder'/'$file2

Expected behavior

ff2.txt is not found, and the upload is interrupted.

Actual behavior

The post-processing tries to handle the upload

Setup

Please describe how you started the server and provide a list of relevant environment variables or configuration files.

POSTPROCESSING_DELAY=10s PROXY_ENABLE_BASIC_AUTH=true OCIS_INSECURE=true PROXY_HTTP_ADDR=0.0.0.0:9200 OCIS_URL=https://host.docker.internal:9200 PROXY_TRANSPORT_TLS_KEY=./ocis.pem PROXY_TRANSPORT_TLS_CERT=./ocis.crt ./ocis/bin/ocis server

Additional context

logs:

{"level":"error","error":"decomposedfs: root has no parent","uploadID":"0645d53a-355c-4aca-9cb5-2177d11c582e","time":"2023-12-07T17:36:02+05:45","message":"could not propagate tree size change"}
{"level":"error","error":"failed to upload file to blobstore: could not open blob '~/.ocis/storage/users/spaces/00/364da3-abb6-47d0-8002-6cd66ed6eea5/blobs' for writing: open ~/.ocis/storage/users/spaces/00/364da3-abb6-47d0-8002-6cd66ed6eea5/blobs: is a directory","uploadID":"1d13ffb8-24bf-4fdd-b321-d5c774fcf353","time":"2023-12-07T17:36:32+05:45","message":"could not finalize upload"}

[update-docs]

Thanks for opening this pull request! The maintainers of this repository would appreciate it if you would create a changelog item based on your changes.