Removed redundant old j2ssh-artemis-plugin.jar

lib/j2ssh/README

-
-j2ssh-artemis-plugin.jar   - artemis plugin
-
-This plugin uses the Java implementation of the SSH version 2
-protocol from:
-
-http://freshmeat.net/projects/sshtools-j2ssh/
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-j2ssh-0.2.9 - is the release being used.
-
-Currently the following jars are needed to be put into this 
-directory:
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-commons-logging.jar
-j2ssh-core.jar
-jce-jdk13-119.jar
-xercesImpl.jar
-
-(which are incorporated or can be built from the j2ssh download)
-