cloudstorage: adapt tests

The code assumes that prefs.cloud_base_url is non NULL. Allowing that to
be NULL makes no sense during normal operation of the app. Yet, most of
the tests don't initialize the prefs at all.

Making things worse, if we do correctly initialize the prefs (so as to
reasonably approximate the behavior when running the app), things break
because some of the reference outputs assume that the prefs are unset.
This deserves fixing.

For now, simply make sure that cloud_base_url is set for all the tests
that try to parse files.

Additionally, the semantics how cloud_base_url is saved to disk have
changed, so adjust the test for those prefs accordingly.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

tests/testparse.cpp

@@ -35,6 +35,7 @@ void TestParse::initTestCase()
 {
 	/* we need to manually tell that the resource exists, because we are using it as library. */
 	Q_INIT_RESOURCE(subsurface);
+	prefs.cloud_base_url = strdup(default_prefs.cloud_base_url);
 }
 
 void TestParse::init()