[fix] fix session closed error

src/sakia/data/connectors/bma.py

@@ -364,8 +364,8 @@ class BmaConnector:
         replies = []
 
         if len(endpoints) > 0:
-            for endpoint in endpoints:
-                async with aiohttp.ClientSession() as session:
+            async with aiohttp.ClientSession() as session:
+                for endpoint in endpoints:
                     self._logger.debug("Trying to connect to: " + str(endpoint))
                     _client = client.Client(
                         endpoint, session, proxy=self._user_parameters.proxy()
@@ -373,7 +373,8 @@ class BmaConnector:
                     reply = asyncio.ensure_future(_client(request, **req_args))
                     replies.append(reply)
 
-            result = await asyncio.gather(*replies, return_exceptions=True)
+                result = await asyncio.gather(*replies, return_exceptions=True)
+
             return tuple(result)
         else:
             raise NoPeerAvailable("", len(endpoints))