improvements in dbmemory. Change yaml.load to save_load

Change-Id: I577efa64a8c1503a084cb21b49ec7e3665b7b56f
Signed-off-by: tierno <alfonso.tiernosepulveda@telefonica.com>
diff --git a/osm_common/msgkafka.py b/osm_common/msgkafka.py
index bc9147d..1e22c9f 100644
--- a/osm_common/msgkafka.py
+++ b/osm_common/msgkafka.py
@@ -136,11 +136,12 @@
 
             async for message in self.consumer:
                 if callback:
-                    callback(message.topic, yaml.load(message.key), yaml.load(message.value), **kwargs)
+                    callback(message.topic, yaml.safe_load(message.key), yaml.safe_load(message.value), **kwargs)
                 elif aiocallback:
-                    await aiocallback(message.topic, yaml.load(message.key), yaml.load(message.value), **kwargs)
+                    await aiocallback(message.topic, yaml.safe_load(message.key), yaml.safe_load(message.value),
+                                      **kwargs)
                 else:
-                    return message.topic, yaml.load(message.key), yaml.load(message.value)
+                    return message.topic, yaml.safe_load(message.key), yaml.safe_load(message.value)
         except KafkaError as e:
             raise MsgException(str(e))
         finally: