tests/connection-test: Update expected events for GLib 2.67

See GLib commit f0a7b147806e852e2090eeda6e4e38f7d3f52b52 for full
details, but now the extra RESOLVING event is not emitted any more.

To cater for situations where libsoup is run against an older version of
GLib, keep a runtime check for older versions.

Fixes: #215