Fix thumbnails for playlist clips having a different resolution than project profile.

Related to #1314

src/bin/projectclip.cpp

@@ -658,7 +658,7 @@ std::shared_ptr<Mlt::Producer> ProjectClip::thumbProducer()
             // Xml producers can corrupt the profile, so enforce width/height again after loading
             int profileWidth = profile->width();
             int profileHeight= profile->height();
-            m_thumbsProducer.reset(new Mlt::Producer(*profile, mltService.toUtf8().constData(), mltResource.toUtf8().constData()));
+            m_thumbsProducer.reset(new Mlt::Producer(*profile, "consumer", mltResource.toUtf8().constData()));
             profile->set_width(profileWidth);
             profile->set_height(profileHeight);
         } else {

src/jobs/cliploadtask.cpp

@@ -242,7 +242,7 @@ void ClipLoadTask::generateThumbnail(std::shared_ptr<ProjectClip>binClip, std::s
             if (mltService.startsWith(QLatin1String("xml"))) {
                 int profileWidth = profile->width();
                 int profileHeight= profile->height();
-                thumbProd.reset(new Mlt::Producer(*profile, mltService.toUtf8().constData(), mltResource.toUtf8().constData()));
+                thumbProd.reset(new Mlt::Producer(*profile, "consumer", mltResource.toUtf8().constData()));
                 profile->set_width(profileWidth);
                 profile->set_height(profileHeight);
             } else {