EKF.update() doesn't accept mag data

[tkschuler]

EKF only works with magnetometer data if the one liner ekf() function is called without using ekf.update().

If mag data is included in the update function, the R covariance matrix isn't initialized properly and is a 3x3 instead of 6x6.

[AlexVaith]

for me, it works if I include the complete mag array into the ekf() call. I do not know if this is correct though. Then I can add the mag vector of the current timestamp into the update function without an error-