Fix typo

Author: BurntimeX

wcfsetup/install/files/lib/system/interaction/IInteraction.class.php

@@ -25,7 +25,7 @@ public function render(DatabaseObject $object): string;
     public function renderInitialization(string $containerId): ?string;
 
     /**
-     * Returns true if this interaction is available for the given object
+     * Returns true if this interaction is available for the given object.
      */
     public function isAvailable(DatabaseObject $object): bool;