fix LOGBACK-1703

Signed-off-by: Ceki Gulcu <ceki@qos.ch>

Author: ceki

logback-classic/src/main/java/module-info.java

@@ -32,6 +32,7 @@
   exports ch.qos.logback.classic.jul;
   exports ch.qos.logback.classic.layout;
   exports ch.qos.logback.classic.log4j;
+  exports ch.qos.logback.classic.model;
   exports ch.qos.logback.classic.net;
   exports ch.qos.logback.classic.net.server;
   exports ch.qos.logback.classic.pattern;