Add ThreadGetMyExternalIP to net thread group
Add ThreadGetMyExternalIP to net thread group

Fixes #3372 -- crash at shutdown.

Kefkius/clams,dooglus/clams,nochowderforyou/clams,dooglus/clams,robvanmieghem/clams,nochowderforyou/clams,nochowderforyou/clams,dooglus/clams,Kefkius/clams,Jheguy2/Mercury,Kefkius/clams,robvanmieghem/clams,robvanmieghem/clams,thunderrabbit/clams,Kefkius/clams,robvanmieghem/clams,nochowderforyou/clams,Jheguy2/Mercury,thunderrabbit/clams,dooglus/clams,dooglus/clams,Kefkius/clams,robvanmieghem/clams,Jheguy2/Mercury,thunderrabbit/clams,thunderrabbit/clams,thunderrabbit/clams,nochowderforyou/clams,Jheguy2/Mercury,Jheguy2/Mercury