Fix bug to raise vimconnException if image not found at VIM; fix bug in vimconn_openstack to accept image lookups only by name

Change-Id: Ia4d42dc5f69f07f2f3646916cfd6d414b702c5ea
Signed-off-by: garciadeblas <gerardo.garciadeblas@telefonica.com>
diff --git a/vimconn_openstack.py b/vimconn_openstack.py
index cdd1178..addee3a 100644
--- a/vimconn_openstack.py
+++ b/vimconn_openstack.py
@@ -652,7 +652,7 @@
             filtered_list = []
             for image in image_list:
                 image_dict=self.glance.images.get(image.id)
-                if image_dict['checksum']==filter_dict.get('checksum'):
+                if filter_dict.get('checksum') == None or image_dict['checksum']==filter_dict.get('checksum'):
                     filtered_list.append(image)
             return filtered_list
         except (ksExceptions.ClientException, nvExceptions.ClientException, gl1Exceptions.CommunicationError, ConnectionError) as e: