[GSS](6.4.z)Upgrade version of Jsch artifact(0.1.50-->0.1.54) shipped with BxMS.

 ERROR [org.guvnor.structure.backend.repositories.RepositoryServiceImpl] (http-0.0.0.0:8443-6) Error during create repository: java.lang.RuntimeException: ssh://git@bitbucket.hostname.com:7988/repo/rules.git: Algorithm negotiation fail
	at org.guvnor.structure.backend.repositories.git.GitRepositoryBuilder.createFileSystem(GitRepositoryBuilder.java:139) [guvnor-structure-backend-6.5.0.Final-redhat-2.jar:6.5.0.Final-redhat-2]
             .  .  .
Caused by: java.lang.RuntimeException: org.eclipse.jgit.api.errors.TransportException: ssh://git@bitbucket.hostname.com:7988/repo/rules.git: Algorithm negotiation fail
	at org.uberfire.java.nio.fs.jgit.util.JGitUtil.cloneRepository(JGitUtil.java:289) [uberfire-nio2-jgit-0.9.0.Final-redhat-3.jar:0.9.0.Final-redhat-3]
               . . . 
Caused by: org.eclipse.jgit.api.errors.TransportException: ssh://git@bitbucket.hostname.com:7988/repo/rules.git: Algorithm negotiation fail
	at org.eclipse.jgit.api.FetchCommand.call(FetchCommand.java:135) [org.eclipse.jgit-4.4.1.201607150455-r.jar:4.4.1.201607150455-r]
	 . . .
Caused by: org.eclipse.jgit.errors.TransportException: ssh://git@bitbucket.hostname.com:7988/repo/rules.git: Algorithm negotiation fail
	at org.eclipse.jgit.transport.JschConfigSessionFactory.getSession(JschConfigSessionFactory.java:159) [org.eclipse.jgit-4.4.1.201607150455-r.jar:4.4.1.201607150455-r]
              . . . 
Caused by: com.jcraft.jsch.JSchException: Algorithm negotiation fail
	at com.jcraft.jsch.Session.receive_kexinit(Session.java:582) [jsch-0.1.50.jar:]
	at com.jcraft.jsch.Session.connect(Session.java:320) [jsch-0.1.50.jar:]
	at org.eclipse.jgit.transport.JschConfigSessionFactory.getSession(JschConfigSessionFactory.java:116) [org.eclipse.jgit-4.4.1.201607150455-r.jar:4.4.1.201607150455-r]
	... 100 more