Remove bogus argument to ->get(), which fail on HTTP::Message >= 5.05

The documentation for ->get states:

    $ua->get( $url , $field_name => $value, ... )

The later arguments are expected to be headers which will be added to
the request, via HTTP::Request, which isa HTTP::Message.  Hence,
t/web/compilation_errors.t was adding a bogus header whose _name_ was
"GET http://server:port/path" and whose value was undef.  HTTP::Message
5.05 rightly errors on being passed this, complaining:

    Illegal field name 'GET http://localhost:7582//index.html'

Remove the bogus second argument to ->get, which has been present since
e1f253e.
Ensure that tickets are destroyed before global destruction, in more recent perl

Perl 5.14 and above undergo global destruction in a different order,
causing tests to fail because of disorderly teardown and transaction
batch.  Explicitly clear out @tickets to ensure that they do not get
DESTROYed during global destruction.
destroy more tickets and objects before global destruction for modern perl

see also commit 7468211
Merge branch '3.8/test-compat' into 3.8-trunk