GX-Entwicklung

Steps to reproduce:

1. Gambio Admin > Modules > Modules-Center: install "Gift vouchers and coupons" module
2. Create a coupon
3. Select the coupon in the overview and click on the "Report" button, to open the report page
4. Open Gambio Admin > Toolbox > Show Logs page

Expected:
No error is written to the error-handler log

Actual:
WARNING: Use of undefined constant TEXT_HEADING_COUPON_REPORT - assumed 'TEXT_HEADING_COUPON_REPORT' (this will throw an Error in a future version of PHP) log entry is written

Furthermore:
The "Report" button also has the wrong translation in German (Melden instead of Report).