LibsocialwebTest: don't try to keep ownership of name through tear_down()
LibsocialwebTest: don't try to keep ownership of name through tear_down()

This is a step towards replacing with-session-bus*.sh with GTestDBus,
which cleans up our D-Bus connection while the test is still running.
If we do that without this change, then the NameLost callback is triggered
when we get disconnected from D-Bus, causing an assertion failure.

This also should reduce circular references, by making sure closures
that contain "this" get cleaned up.

Bug: https://bugzilla.gnome.org/show_bug.cgi?id=690830
Signed-off-by: Simon McVittie <2b470b34502dbf3ba4bcc04ea7e64f4e0e104f33@collabora.co.uk>
Reviewed-by: Philip Withnall <3ba3974e96044dcde818e6310ed799abe10671d4@tecnocode.co.uk>

GNOME/folks,pwithnall/folks,GNOME/folks,pwithnall/folks,pwithnall/folks,renatofilho/folks2,renatofilho/folks2,renatofilho/folks2,renatofilho/folks,renatofilho/folks,renatofilho/folks,renatofilho/folks2,renatofilho/folks,GNOME/folks