missing parameter(s) in GET request causes internal error 500

Afer upgrading from 0.2.2 to 0.2.6 (git master) I've started to receive internal error codes 500.

After debugging I've figured out that I receive the error when the location is send to the API.

At version 0.2.2, the public link looks as follows:

https://SERVER/apps/phonetrack/log/gpslogger/session/yourname?lat=%LAT&lon=%LON&sat=%SAT&alt=%ALT&acc=%ACC&timestamp=%TIMESTAMP&bat=%BATT

However, in 0.2.6 the link shown by the GUI looks like this:

https://SERVER/apps/phonetrack/log/gpslogger/session/yourname?lat=%LAT&lon=%LON&sat=%SAT&alt=%ALT&acc=%ACC&speed=%SPD&bearing=%DIR&timestamp=%TIMESTAMP&bat=%BATT

In any case, the client app still uses the "old" 0.2.2 link and thus receives an internal error 500. In my opinion the server (API) should not return an internal error code, because a parameter is missing from the GET request. The only side effect of not using a parameter should be that this particular data point is not recorded.