Update apns-conf.xml

I changed the APN type for Telenor Serbia provider. APN type was set to "default,supl,mms" for both internet and mms. I had to change this manualy since I am using CyanogenMod (CM7) and it is causing of sending mms to get stuck forever.
I just set APN type for internet to "default,supl" and for mms just "mms"