Always use a full filesystem path when including the FTP handler in PemFTP. This prevents other files in the includes directory being scanned/included accidentally.
See #29628

Built from https://develop.svn.wordpress.org/trunk@30310


git-svn-id: http://core.svn.wordpress.org/trunk@30309 1a063a9b-81f0-0310-95a4-ce76da25c4cd