MAPG-199 fix issues found by PHPStan

src/Session/DatabaseSessionHandler.php

@@ -69,7 +69,7 @@ class DatabaseSessionHandler implements ISessionHandler
         return true;
     }
 
-    public function gc($maxlifetime): int
+    public function gc($maxlifetime): bool
     {
         // empty on purpose
         // old sessions are deleted by MaintainDatabaseCommand
@@ -84,7 +84,7 @@ class DatabaseSessionHandler implements ISessionHandler
 
     public function validateId($id): bool
     {
-        return preg_match('/^[a-f0-9]{32}$/', $id);
+        return preg_match('/^[a-f0-9]{32}$/', $id) === 1;
     }
 
     public function updateTimestamp($id, $data): bool