mark selectbox as disabled if needed

Author: andris9

views/partials/oauth_form.hbs

@@ -566,13 +566,19 @@
             }
             let projectId = projectIdElm.value;
             if (projectId) {
+                let unselected = !pubSubAppElm.value
+
                 pubSubAppElm.querySelectorAll('option').forEach(entry => {
                     if (entry.value && entry.dataset.project !== projectId) {
                         entry.classList.add('d-none');
                         entry.disabled = true;
                     } else {
                         entry.classList.remove('d-none');
                         entry.disabled = false;
+                        if (unselected) {
+                            entry.selected = true;
+                            unselected = false;
+                        }
                     }
                 });
             }