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

Fixes #7363

library/cloud/docker

@@ -507,7 +507,9 @@ class DockerManager:
             running_image, running_tag = self.get_split_image_tag(i['Image'])
             running_command = i['Command'].strip()
 
-            name_matches = (name and name in i['Names'])
+            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)
             # if a container has an entrypoint, `command` will actually equal