fix: undefined filename in livephoto

[skjnldsv]

TypeError: Cannot read properties of undefined (reading 'startsWith')
    at getDavPath (viewer-main.mjs?v=4627e4c8-1765:27012:16)
    at VueComponent.livePhotoDavPath (viewer-main.mjs?v=46…e4c8-1765:121693:31)
    at Watcher2.get (viewer-main.mjs?v=4627e4c8-1765:2300:30)
    at Watcher2.evaluate (viewer-main.mjs?v=4627e4c8-1765:2371:25)
    at VueComponent.computedGetter [as livePhotoDavPath] (viewer-main.mjs?v=4627e4c8-1765:3561:17)
    at VueComponent.livePhotoSrc (viewer-main.mjs?v=46…e4c8-1765:121689:45)

No idea how to properly reproduce this, but I've had reports and experienced it myself

[Antreesy]

LGTM

[skjnldsv]

/compile amend /

[skjnldsv]

/backport to stable29

[skjnldsv]

/backport to stable28

[backportbot]

The backport to stable28 failed. Please do this backport manually.

# Switch to the target branch and update it
git checkout stable28
git pull origin stable28

# Create the new backport branch
git checkout -b backport/2418/stable28

# Cherry pick the change from the commit sha1 of the change against the default branch
# This might cause conflicts, resolve them
git cherry-pick bf06f3f6

# Push the cherry pick commit to the remote repository and open a pull request
git push origin backport/2418/stable28

Error: No changes found in backport branch

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Learn more about backports at https://docs.nextcloud.com/server/stable/go.php?to=developer-backports.