limit callsign length

Author: Mark Jessop

index.html

@@ -292,7 +292,7 @@ <h2><i class="icon-car rfloat"></i>Chase Mode</h2>
             </div>
             <div class="row">
                 <span>Callsign</span>
-                <span class="r"><input type="text" id="cc_callsign" style="width: 140px;"/></span>
+                <span class="r"><input type="text" id="cc_callsign" style="width: 140px;" maxlength="15"/></span>
             </div>
             <div class="row">
                 <span><b>Notice: If you enable this, your location will be uploaded to SondeHub, making it publicly visible on the map for up to 12 hours.</b></span>