add a missing period

README.textile

 * "SMTP":https://en.wikipedia.org/wiki/Simple_Mail_Transfer_Protocol over SSL via Postfix, including a nice set of "DNSBLs":https://en.wikipedia.org/wiki/DNSBL to discard spam before it ever hits your filters.
 * Webmail via "Roundcube":http://www.roundcube.net/.
 * Jabber/"XMPP":http://xmpp.org/ instant messaging via "Prosody":http://prosody.im/.
-* An RSS Reader via "Selfoss":http://selfoss.aditu.de/
+* An RSS Reader via "Selfoss":http://selfoss.aditu.de/.
 * Virtual domains for your email, backed by "MySQL":https://www.mysql.com/.
 * Secure on-disk storage for email and more via "EncFS":http://www.arg0.net/encfs.
 * Spam fighting via "DSPAM":http://dspam.sourceforge.net/ and "Postgrey":http://postgrey.schweikert.ch/.