corrected Telekom DE APNs

user should be "t-mobile" and password should be "tm".
For mms apn:
https://www.t-mobile.de/handy-hilfe/0,23626,26974-_,00.html#/samsung/galaxy-s5/mms-und-sms/usecase/mms-manuelle-einstellung/9

For internet apn:
https://www.t-mobile.de/handy-hilfe/0,23626,26974-_,00.html#/samsung/galaxy-s5/internet/usecase/internetverbindung-manuelle-einstellung/11

In general, for APN config: https://www.t-mobile.de/handy-hilfe/

Change-Id: I71e03eaf31d9d9d3b34b0fcb7e4ac7de9c3180d9