Fix bug 2142: Debug mode in Pebble Charms is not working

Change-Id: Icca7e2b3a38b0c9ca4859138931e2c92566fd1d9
Signed-off-by: Guillermo Calvino <guillermo.calvino@canonical.com>
diff --git a/installers/charm/osm-nbi/src/charm.py b/installers/charm/osm-nbi/src/charm.py
index 454b155..23ab054 100755
--- a/installers/charm/osm-nbi/src/charm.py
+++ b/installers/charm/osm-nbi/src/charm.py
@@ -113,7 +113,8 @@
             # Eventually it will become ready after the first pebble-ready event.
             check_container_ready(self.container)
 
-            self._configure_service(self.container)
+            if not self.debug_mode.started:
+                self._configure_service(self.container)
             self._update_ingress_config()
             self._update_nbi_relation()
             # Update charm status