Safely omit IP if it is not available.

web/templates/base.html

@@ -15,7 +15,7 @@
 				<li><a href="/" {% if page == 'network' %} class="selected" {% endif %}>Network</a></li>
 				<li><a href="/about"{% if page == 'about' %} class="selected" {% endif %}>About</a></li>
 				<li><a href="https://github.com/zielmicha/fc00.org">Source</a></li>
-				<li><tt>{{ ip }}</tt></li>
+				<li><tt>{% if ip is not none %}{{ ip }}{% endif %}</tt></li>
 			</ul>
 		</div>
 

web/web.py

@@ -5,7 +5,10 @@ app = Flask(__name__)
 app.config.from_pyfile('web_config.cfg')
 
 def get_ip():
+        try:
                 ip = request.headers['x-real-ip']
+        except KeyError:
+                ip = None
         if ip == '10.18.3.20':
                 ip = request.headers['x-atomshare-real-ip']
         return ip