fix typo

public/index.html

@@ -21,7 +21,7 @@
             <div id="info-ip" class="info">Your IP Address is <span id="ip"></span>.</div>
             <div id="error-browser" class="error">Your Browser is not supported. Please try another one.</div>
             <div id="error-external" class="error">Your IP Address does not belong to the StuStaNet! You seem to be using either mobile Internet or some sort of Proxy or VPN!</div>
-            <div id="error-proxy" class="error">You are not a StuStaNet member and did not configure the proxy server. <a href="http://conntest.stustanet.de/nomember">Click here to for further information</a>.</div>
+            <div id="error-proxy" class="error">You are not a StuStaNet member and did not configure the proxy server. <a href="http://conntest.stustanet.de/nomember">Click here for further information</a>.</div>
             <div id="error-blocked" class="error">Your Internet Access is blocked due to malware or malicious behavior. <a href="http://conntest.stustanet.de/blocked">Click here to view the blocking page with more information</a>.</div>
             <div id="error-unknown" class="error">An unknown error occurred. Please contact a network administrator and attach the log at the bottom of this page.</div>
             <div id="warn-nat" class="warn">Network Address Translation (NAT) is not working, meaning that many application will not work as expected. However, this is expected, as you do not seem to be a StuStaNet member. NAT is a members-only service.</div>