Cluster/DHT: Changing rename log severity

Changing log level for a rename message from debug
to info to improve debuggability

Change-Id: I53031fcf97fffd62095692477330ecde0cf47dcd
BUG: 1130888
Signed-off-by: Nithya Balachandran <nbalacha@redhat.com>
Reviewed-on: http://review.gluster.org/8582
Reviewed-by: Vijay Bellur <vbellur@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>