refactor(InternalMeetingStatsService): 유저 객체로 부터 orgId를 가져와서 반환하도록 리팩토링

main/src/main/java/org/sopt/makers/crew/main/internal/service/InternalMeetingStatsService.java

@@ -28,6 +28,6 @@ public ApprovedStudyCountResponseDto getApprovedStudyCountByOrgId(Integer orgId)
 		Long approvedStudyCount = applyRepository.findApprovedStudyCountByOrgId(MeetingCategory.STUDY,
 			EnApplyStatus.APPROVE, user.getOrgId());
 
-		return ApprovedStudyCountResponseDto.of(orgId, approvedStudyCount);
+		return ApprovedStudyCountResponseDto.of(user.getOrgId(), approvedStudyCount);
 	}
 }