logback 2.1.9 (#39)

Additional hardening in response to CVE-2021-42550. 

http://logback.qos.ch/news.html

Author: Daniel Norberg

pom.xml

@@ -80,12 +80,12 @@
     <dependency>
       <groupId>ch.qos.logback</groupId>
       <artifactId>logback-classic</artifactId>
-      <version>1.2.8</version>
+      <version>1.2.9</version>
     </dependency>
     <dependency>
       <groupId>ch.qos.logback</groupId>
       <artifactId>logback-core</artifactId>
-      <version>1.2.8</version>
+      <version>1.2.9</version>
     </dependency>
     <dependency>
       <groupId>net.logstash.logback</groupId>