pjsua2 register interval

[aduiliosilva@xxxxxxxxxxxxxxxx (Aduílio)]

I'm using pjsua2 version 2.2.1 built to Android.
I'm creating an Account and passing register timeout less than 600 
seconds (accCfg.getRegConfig().setTimeoutSec(timeout)), but pjsua2 uses 
600 on timeout register interval.
How can I change this minimun value?

Aduilio