`ezwtServerCallFunctions::updatePriority()` calls `eZContentCacheManager::clearContentCache()` directly on `ezpublish_legacy/extension/ezwt/classes/ezwtservercallfunctions.php`.

Therefore, if you use the toolbar and you are changing the priority, the cache will be expired - no matter if it's activated or not.

Current behaviour
`ezwtServerCallFunctions::updatePriority()` calls `eZContentCacheManager::clearContentCache()` directly

Expected behaviour
`ezwtServerCallFunctions::updatePriority()` should call `eZContentCacheManager::clearContentCacheIfNeeded()`