update external error message

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!<br />
-            Please make sure you are not using mobile internet, deactivated all VPNs / data savers / or third-party proxies and try again.</div>
+            Please make sure you are not using your mobile data and deactivated all VPNs, data-savers or third-party proxies and try again.</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>