remove some redundant php closing tags

api/index.php

classes/api.php

classes/auth/base.php

classes/backend.php

classes/db.php

classes/db/mysqli.php

classes/db/pdo.php

classes/db/pgsql.php

classes/db/prefs.php

classes/db/stmt.php

classes/dbupdater.php

classes/dlg.php

classes/feedenclosure.php

classes/feeditem.php

classes/feeditem/atom.php

classes/feeditem/common.php

classes/feeditem/rss.php

classes/feedparser.php

classes/handler.php

classes/handler/protected.php