Remove profile_pic from default fields when getting a user.

[MarGul]

Facebook has updated their User Profile API in regards to GDPR. This looks like it should only involve Europe but people have been reporting that they are affected even outside of Europe.

This is the error message you will get: (#10) This action was not submitted due to new privacy rules in Europe. See developer documentation for more info

You can have a look at the Changelog where it says under December 16, 2020 that

User Profile API will be supported for all fields except for profile_pic. API calls with profile_pic field will return an error message.

The PR removes the profile_pic from default as a quick fix. Might have to take a look at doing some changes at getProfilePic methods and so on.

[semseysandor]

The profile_pic feature was restored on April 1, 2021 (along many more since then).
From the Changelog

Messenger API features restored as of 4/13/2021:
User Profile API profile_pic field

I've just tested (from Europe) and Facebook returns profile picture. So I think this PR is not necessary now, as it removes a working feature.