Require --debug log in bug report issue template.

.gitlab/issue_templates/Bug.md

@@ -9,7 +9,10 @@
 
 ### Debug log
 <!-- Paste a debug log of the failing command (add --debug option) between the markers below (to keep raw debug format).-->
+<!-- We need a lot of information from the debug log; without it, we cannot process your report. -->
+<!-- Debug log does not contain any private information. Do not paste private data; we'll ask you for more information if needed. -->
 ```
 Output with --debug option:
 
 ```
+<!-- NOTE: WITHOUT DEBUG LOG, THE BUG REPORT WILL BE CLOSED. ALSO, PLEASE DO NOT TRY TO REMOVE PARTS OF THE DEBUG LOG! -->