Merge pull request #478 from woowacourse-teams/feature/#477

금액 입력할 때 1 입력 후 안 지워지는 문제 해결

frontend/src/constants/regex.ts

@@ -1,5 +1,5 @@
 export const REGEX = {
   ONLY_LETTER: /^[A-Za-z가-힣ㄱ-ㅎ]+$/g,
-  ALPHABET_AND_KOREAN_CHARACTERS: /^[a-zA-Zㄱ-ㅎㅏ-ㅣ가-힣]*$/,
+  ALPHABET_AND_KOREAN_CHARACTERS: /^[a-zA-Zㄱ-ㅎㅏ-ㅣ가-힣]+$/,
   HTTP_TO_HTTPS: /^http(?!s)/,
 };