Issue #4068: Ignore Kernel/cpan-lib/local

In the previous version there was a leading '!' which declared the opposite.

.dockerignore

@@ -91,7 +91,7 @@ bin/Cron.sh
 **/*.chain
 
 # do not keep temporary files from Perl module installation
-!Kernel/cpan-lib/local
+Kernel/cpan-lib/local
 
 # The Photoshop source file, the *.psd files, are not needed in the Docker image
 ./var/httpd/htdocs/skins/Agent/default/img/source/