fix: logback의 loki 관련 설정 수정

- logback-spring.xml 파일의 loki appender 내부 url의 환경변수화

Author: 7zrv

src/main/resources/logback-spring.xml

@@ -31,7 +31,7 @@
     <appender name="LOKI" class="com.github.loki4j.logback.Loki4jAppender">
 
         <http>
-            <url>http://loki:3100/loki/api/v1/push</url>
+            <url>${LOKI_URL}</url>
             <connectionTimeoutMs>30000</connectionTimeoutMs>
             <requestTimeoutMs>15000</requestTimeoutMs>
             <maxRetries>3</maxRetries>