Remove bogus warning about vir$OBJECTGetConnect functions

Remove bogus warning about vir$OBJECTGetConnect functions

The API docs for the various vir$OBJECTGetConnect functions
contain a warning

  WARNING: When writing libvirt bindings in other languages, do
  not use this function.  Instead, store the connection and
  the domain object together.

There is no reason why language bindings should not use this
method, and indeed the Perl, Python, and Go bindings all use
these methods.

This warning was originally added back in

  commit 3edb4bc9fb1b451599df58420d61ffd73633cead
  Author: Daniel Veillard <veillard@redhat.com>
  Date:   Tue Jul 24 15:32:55 2007 +0000

    * libvirt.spec.in NEWS docs/* po/*: preparing release 0.3.1
    * src/libvirt.c python/generator.py: some cleanup and warnings
      from Richard W.M. Jones

IIUC, the rational was that these APIs do not need to be
directly exposed to the non-C language, as the language
can expose the same concept itself by storing the original
virConnectPtr object alongside the virDomainPtr.  There's
no reason to mandate such an approach though - it is valid
for languages to expose this directly if that suits their
needs better.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>