If students are in group, they can no longer enqueue again

Closes #661 (closed)

src/main/java/nl/tudelft/queue/service/RequestService.java

@@ -146,7 +146,6 @@ public class RequestService {
 			if (!currentlyEnqueuing.add(personId))
 				return;
 
-
 			if (request instanceof LabRequest labRequest) {
 
 				if (labRequest.getTimeSlot() != null && !labRequest.getTimeSlot().canTakeSlot()) {