v4l2src: Ensure internal pool activation

Before we would hit an assertion "'gst_buffer_pool_is_active (bpool)' failed"
if the internal pool was not used to push buffer downstrea, hence not
given to the baseclass.

https://bugzilla.gnome.org/show_bug.cgi?id=732912
tests/souphttpsrc: Skip consistently failing test

The test in question tries to connect to Virgin Radio Ogg stream at
smgradio.com, but this server is no longer operational.