Make sure the docker data has a "Names" field before using it

Fixes #7363

cloud/docker

@@ -507,6 +507,8 @@ class DockerManager:
             running_image, running_tag = self.get_split_image_tag(i['Image'])
             running_command = i['Command'].strip()
 
+            name_matches = False
+            if i["Names"]:
                 name_matches = (name and name in i['Names'])
             image_matches = (running_image == image)
             tag_matches = (not tag or running_tag == tag)