patch existing shares on access, if timezone is UTC

Signed-off-by: dartcafe <github@dartcafe.de>

Author: dartcafe

lib/Service/ShareService.php

@@ -163,7 +163,8 @@ public function getEffectiveShare(?string $token = null): Share {
 		if ($effectiveShare->getType() === Share::TYPE_EXTERNAL) {
 			$needsUpdate = false;
 
-			if (!$effectiveShare->getTimeZoneName()) {
+			// TODO: Remove UTC check after migration period — patches shares incorrectly saved with UTC default
+			if (!$effectiveShare->getTimeZoneName() || $effectiveShare->getTimeZoneName() === 'UTC') {
 				$clientTz = $this->userSession->getClientTimeZoneName();
 				if ($clientTz) {
 					$effectiveShare->setTimeZoneName($clientTz);