fixed build problem

Signed-off-by: Stephan Richter <s.richter@srsoftware.de>

backend/build.gradle.kts

@@ -59,5 +59,6 @@ tasks.jar {
         ":time:jar",
         ":translations:jar",
         ":user:jar",
-        ":web:jar")
+        ":web:jar",
+        ":wiki:jar")
 }