Fix BaseHTTPAdapter for the SSL case

Signed-off-by: Ulysses Souza <[email protected]>

Author: Ulysses Souza

docker/transport/basehttpadapter.py

@@ -3,4 +3,6 @@
 
 class BaseHTTPAdapter(requests.adapters.HTTPAdapter):
     def close(self):
-        self.pools.clear()
+        super(BaseHTTPAdapter, self).close()
+        if hasattr(self, 'pools'):
+            self.pools.clear()