update logback to 1.3.15

Author: maximthomas

pom.xml

@@ -1080,7 +1080,7 @@
   		<dependency>
 	      <groupId>ch.qos.logback</groupId>
 	      <artifactId>logback-classic</artifactId>
-	      <version>1.2.13</version>
+	      <version>1.3.15</version>
 	    </dependency>
     </dependencies>
   </dependencyManagement>