fix(provisioning_api): Close unterminated string literal in AppConfigController

Commit 626fadd accepted a GitHub review suggestion verbatim that
was missing the closing single quote on 'yes', producing a fatal PHP
parse error that took out every integration-sqlite job (OCS endpoints
returned 998 instead of 100).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Signed-off-by: Stephen Cuppett <steve@cuppett.com>

Author: cuppett

apps/provisioning_api/lib/Controller/AppConfigController.php

@@ -203,7 +203,7 @@ protected function verifyConfigKey(string $app, string $key, string $value) {
 			throw new \InvalidArgumentException('The given key can not be set');
 		}
 
-		if ($app === 'core' && $key === 'encryption_enabled' && $value !== 'yes) {
+		if ($app === 'core' && $key === 'encryption_enabled' && $value !== 'yes') {
 			throw new \InvalidArgumentException('The given key can not be set');
 		}