Update apns-conf.xml

Hello,
I have noticed that cm doesn't have correct values for Vodafone Albania and is missing three other operators, i decided to contribute with this settings (line 528 to 533) and their references:
Vodafone AL: http://www.vodafone.al/vodafone/Automatic_Manual_2581_2.php
AMC: http://www.amc.al/al/samsung-pjesa-i-1705/samsung-galaxy-s4-1717
Eagle Mobile:http://www.apn-settings.info/?p=19
Plus Communications:https://www.plus.al/en/individuals-internet-plus-internet