Logging data validation exceptions in NBI charm

Change-Id: Ie818fd1c7092b64b61ddac5184c5d817a7880f46
Signed-off-by: sousaedu <eduardo.sousa@canonical.com>
diff --git a/installers/charm/nbi/src/charm.py b/installers/charm/nbi/src/charm.py
index f0347e2..7ef9d59 100755
--- a/installers/charm/nbi/src/charm.py
+++ b/installers/charm/nbi/src/charm.py
@@ -367,6 +367,7 @@
                 self.port,
             )
         except ValidationError as exc:
+            LOGGER.exception("Config/Relation data validation error")
             self.unit.status = BlockedStatus(str(exc))
             return