fix: 누락한 어노테이션 추가 (#309)

Author: nayonsoso

src/main/java/com/example/solidconnection/auth/controller/AuthController.java

@@ -114,7 +114,7 @@ public ResponseEntity<Void> quit(
 
     @PostMapping("/reissue")
     public ResponseEntity<ReissueResponse> reissueToken(
-            ReissueRequest reissueRequest
+            @Valid @RequestBody ReissueRequest reissueRequest
     ) {
         ReissueResponse reissueResponse = authService.reissue(reissueRequest);
         return ResponseEntity.ok(reissueResponse);