[Refactor]: 기본 신용점수 50wja (#241)

Author: eunchan96

src/main/java/com/backend/domain/member/entity/Member.java

@@ -45,7 +45,7 @@ public class Member extends BaseEntity {
     @Column(name = "refresh_token", columnDefinition = "TEXT")
     private String refreshToken;
 
-    private int creditScore;
+    private int creditScore = 50;
 
     public void updateRefreshToken(String refreshToken) {
         this.refreshToken = refreshToken;