[AMBARI-22194] Remove accidental jline.internal.Log import

[adoroszlai]

What changes were proposed in this pull request?

While reviewing #493, I was looking for how Ambari Server uses the jline:jline dependency, and found that it only appears once. This single usage was added in c19f363, I believe accidentally, probably as a last minute change, since it is not part of the reviewed patch.

I'd like to replace it with the regular slf4j logger, since the jline one is not properly initialized and simply logs to System.err.

(Note that jline:jline is a transitive dependency, so it is not being removed here. However, if this change is accepted, then #493 won't need to add it as explicit dependency.)

CC @smolnar82

How was this patch tested?

Artificially triggered the exception, compared outputs without and with the change.

Before, ambari-server.out:

[WARN] Unable to deserialize the stack packages JSON, assuming no service dependencies

After, ambari-server.log:

28 Feb 2018 15:25:31,509  WARN [ambari-client-thread-40] VersionDefinitionXml:375 - Unable to deserialize the stack packages JSON, assuming no service dependencies
com.google.gson.JsonSyntaxException: java.lang.IllegalStateException: Expected BEGIN_OBJECT but was STRING at line 1 column 5
...

[asfgit]

Refer to this link for build results (access rights to CI server needed):
https://builds.apache.org/job/Ambari-Github-PullRequest-Builder/868/
Test PASSed.