don't try to parse empty qrJson on add from text

public/scripts/extensions/quick-reply/src/QuickReplySet.js

@@ -241,6 +241,7 @@ export class QuickReplySet {
     }
     addQuickReplyFromText(qrJson) {
         let data;
+        if (qrJson) {
             try {
                 data = JSON.parse(qrJson ?? '{}');
                 delete data.id;
@@ -258,6 +259,9 @@ export class QuickReplySet {
                 // no JSON, use plaintext as QR message
                 data = { message: qrJson };
             }
+        } else {
+            data = {};
+        }
         const newQr = this.addQuickReply(data);
         return newQr;
     }