Reorder members to resolve build warning

[kegilbert]

Description

Reorder fixes warning about ctor setup for member variables:

Compile [ 75.0%]: InternetSocket.cpp                                                                          
[Warning] InternetSocket.h@235,10: 'InternetSocket::_factory_allocated' will be initialized after [-Wreorder] 
[Warning] InternetSocket.h@234,23:   'volatile unsigned int InternetSocket::_pending' [-Wreorder]             
[Warning] InternetSocket.cpp@22,1:   when initialized here [-Wreorder]  

In response to: #7885

Also related: #7886

Pull request type

[ ] Fix
[X] Refactor
[ ] Target update
[ ] Functionality change
[ ] Breaking change

[juhaylinen]

Another PR to fix the same warning #7883

[0xc0170]

Another PR to fix the same warning #7883

That is correct. as that one is already in CI. Let's close this one.