Fix typo

index.php

@@ -223,7 +223,7 @@ if (empty($RCMAIL->user->ID)) {
         $OUTPUT->add_footer(html::div(array('style' => "background:#ef9398; border:2px solid #dc5757; padding:0.5em; margin:2em auto; width:50em"),
             html::tag('h2', array('style' => "margin-top:0.2em"), "Installer script is still accessible") .
             html::p(null, "The install script of your Roundcube installation is still stored in its default location!") .
-            html::p(null, "Please <b>remove</b> the whole <tt>installer</tt> folder from the Roundcube directory because .
+            html::p(null, "Please <b>remove</b> the whole <tt>installer</tt> folder from the Roundcube directory because
                 these files may expose sensitive configuration data like server passwords and encryption keys
                 to the public. Make sure you cannot access the <a href=\"./installer/\">installer script</a> from your browser.")
         ));