Fix [#135] 카테고리 생성 시 startDate null 핸들링

오늘 날짜로 자동 매핑

jaksim/src/main/java/org/sopt/jaksim/category/service/CategoryService.java

@@ -46,7 +46,7 @@ public void create(CategoryCreateRequest categoryCreateRequest) {
                 categoryCreateRequest.name(),
 //                userFacade.getUserByPrincipal().getId(),
                 3L,
-                categoryCreateRequest.startDate(),
+                categoryCreateRequest.startDate() == null ? LocalDate.now() : categoryCreateRequest.startDate(),
                 categoryCreateRequest.endDate());
         category = categoryRepository.save(category);
         msetService.createByCategory(categoryCreateRequest, category.getId());