Only free lus shwow up in popup bugfix.

frontend/src/components/unification/free_lu/FreeLuEdit.vue

@@ -153,14 +153,19 @@
             },
             connect_lus_to_slowal_frame(frame_in_progress) {
                 const frame_in_progress_lus = frame_in_progress ? frames2lexical_units([frame_in_progress]).map(l => {
-                    l.pk = l.id;
-                    l.display = l.str;
+                    l.id = l.id;
+                    l.str = l.str;
                     return l;
                 }) : [];
-                const frame_in_progress_lus_ids = new Set(frame_in_progress_lus.map(l => l.pk));
+                const free_lus = this.free_lexical_units.map(l => {
+                    l.id = l.pk;
+                    l.str = l.display;
+                    return l;
+                });
+                const frame_in_progress_lus_ids = new Set(frame_in_progress_lus.map(l => l.id));
                 const lusSelect = function () {
-                    return this.lexical_units.concat(this.free_lexical_units).concat(frame_in_progress_lus).map(lu => {
-                        return `<label><input type="checkbox" ${frame_in_progress_lus_ids.has(lu.pk) ? 'checked' : ''} name="lus" value="${lu.pk}" /> ${lu.display}</label><br />`;
+                    return free_lus.concat(frame_in_progress_lus).map(lu => {
+                        return `<label><input type="checkbox" ${frame_in_progress_lus_ids.has(lu.id) ? 'checked' : ''} name="lus" value="${lu.id}" /> ${lu.str}</label><br />`;
                     }).join("");
                 }.bind(this);