Remove version dependen checks and only rely on capabilities

[michaelstingl]

@TheOneRing could you check if this is used?

% curl 'https://demo.owncloud.org/ocs/v1.php/cloud/capabilities?format=json' \
  -u demo:demo | jq '.ocs.data.version'
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100  2117  100  2117    0     0   9974      0 --:--:-- --:--:-- --:--:-- 10377
{
  "major": 10,
  "minor": 9,
  "micro": 1,
  "string": "10.9.1",
  "edition": "Community"
}

(not the status.php)

What is expected? What would happen if it changes to this this? owncloud/ocis#2918 (comment)

[TheOneRing]

As far as I can tell we only use the version from status.php .
A version > 10 is expected for some legacy version checks that should be removed anyhow.

[michaelstingl]

A version > 10 is expected for some legacy version checks that should be removed anyhow.

Everything > 10 is okay? We could turn it up to 11 and more…?

client/src/libsync/account.cpp

Lines 503 to 504 in 2b73fb9

	// Older version which is not "end of life" according to https://github.com/owncloud/core/wiki/Maintenance-and-Release-Schedule
	return serverVersionInt() < makeServerVersion(10, 0, 0) || serverVersion().endsWith(QLatin1String("Nextcloud"));

[TheOneRing]

Supposedly