makes ssh plugin resilient against invalid entries in hosts file

fixes #10238

lib/ansible/plugins/connections/ssh.py

@@ -243,6 +243,8 @@ class Connection(ConnectionBase):
                 tokens = line.split()
                 if not tokens:
                     continue
+
+                if isinstance(tokens, list) and tokens: # skip invalid hostlines
                     if tokens[0].find(self.HASHED_KEY_MAGIC) == 0:
                         # this is a hashed known host entry
                         try: