Correctly remove apps without any releases

[nickvergessen]

Not sure how this worked in the past, but it seems to be broken in the original fix aswell:
95c9e0e

Anyway clearing the data and afterwards removing empty apps solves the issue for me.

Fix #16771

---

When you try to test this, you need to comment out the caching:

server/lib/private/App/AppStore/Fetcher/Fetcher.php

Lines 154 to 162 in 8e278a2

	// If the timestamp is older than 300 seconds request the files new
	if ((int)$jsonBlob['timestamp'] > ($this->timeFactory->getTime() - self::INVALIDATE_AFTER_SECONDS)) {
	return $jsonBlob['data'];
	}
	if (isset($jsonBlob['ETag'])) {
	$ETag = $jsonBlob['ETag'];
	$content = json_encode($jsonBlob['data']);
	}

And make sure you are on the beta channel:

server/lib/private/legacy/util.php

Lines 524 to 525 in d040954

	OC_Util::loadVersion();
	return \OC::$server->getConfig()->getSystemValue('updater.release.channel', self::$versionCache['OC_Channel']);

If you do this on stable16 with talk enable, it will correctly tell you talk has no 17 update atm.

[nickvergessen]

/backport to stable16

[nickvergessen]

/backport to stable15

[tobiasKaminsky]

Tested & works 👍

[backportbot-nextcloud]

backport to stable16 in #16818

[rullzer]

/backport to stable15

[backportbot-nextcloud]

The backport to stable15 failed. Please do this backport manually.

[rullzer]

Needs a manual backport to stable15