bean: Array concatenated with a String

http://docs.oracle.com/javase/1.5.0/docs/api/java/util/Arrays.html#toString(java.lang.Object[])

Change-Id: I42090bf534a9a59fa97061ec2855f79328b1dd45
Reviewed-on: https://gerrit.libreoffice.org/11478
Reviewed-by: Noel Grandin <noelgrandin@gmail.com>
Tested-by: Noel Grandin <noelgrandin@gmail.com>