No group option did not count for allAllowed in Lab.java

src/main/java/nl/tudelft/ewi/queue/model/Lab.java

@@ -551,7 +551,7 @@ public class Lab implements Serializable {
     }
 
     public boolean allAllowed() {
-        return allowedMentorGroups.size() == 0;
+        return !allowWithoutMentorGroup && allowedMentorGroups.size() == 0;
     }
 
     public boolean userAllowedForThisLab(User user) {