Revert "<HACK> Temporarily checkout the last version with javadoc for doc-kurento"

This reverts commit 4bf4abd48691ae923278b5859acce549da479847.
Now that we have kmf-media-api documented again, it is
no longer needed to check out an oldish version.

Change-Id: I33efc0183641db54d669ad2ef3309dadce2a523c