renaming

Co-authored-by: Christoph <tobi@urpost.de>

src/main/java/mops/gruppen2/domain/exception/UserNotFoundException.java

@@ -0,0 +1,8 @@
+package mops.gruppen2.domain.exception;
+
+public class UserNotFoundException extends EventException {
+
+    public UserNotFoundException(String msg) {
+        super(msg);
+    }
+}