add forum id to cdb.json

.cdb.json

@@ -12,5 +12,6 @@
     "license": "LGPL-2.1-or-later",
     "media_license": "CC-BY-SA-4.0",
     "repo": "https://bitbucket.org/minetest_gamers/x_enchanting/src/master/",
-    "issue_tracker": "https://bitbucket.org/minetest_gamers/x_enchanting/issues?status=new&status=open"
+    "issue_tracker": "https://bitbucket.org/minetest_gamers/x_enchanting/issues?status=new&status=open",
+    "forums": 28861
 }