Upgrade logback-classic 1.2.3 -> 1.2.6
diff --git a/pom.xml b/pom.xml
index 92d2134..718cb0e 100644
--- a/pom.xml
+++ b/pom.xml
@@ -111,7 +111,7 @@
             <dependency>
                 <groupId>ch.qos.logback</groupId>
                 <artifactId>logback-classic</artifactId>
-                <version>1.2.3</version>
+                <version>1.2.6</version>
             </dependency>
             <dependency>
                 <groupId>commons-cli</groupId>