fix: Address data differences with D7

#78 (closed)

src/main/java/org/eclipsefoundation/profile/api/MailingListAPI.java

@@ -39,5 +39,6 @@ public interface MailingListAPI {
      */
     @GET
     @Path("/foundation/mailing-list")
-    List<MailingListData> getMailingListsByUsername(@QueryParam("username") String username);
+    List<MailingListData> getMailingListsByUsername(@QueryParam("username") String username,
+            @QueryParam("is_subscribable") Boolean isSubscribable);
 }