fix(libs/ssh): fix wrong exception message

spug_api/libs/ssh.py

@@ -11,7 +11,7 @@ from io import StringIO
 class SSH:
     def __init__(self, hostname, port=SSH_PORT, username='root', pkey=None, password=None, connect_timeout=10):
         if pkey is None and password is None:
-            raise Exception('public key and password must have one is not None')
+            raise Exception('private key and password cannot both be None')
         self.client = None
         self.arguments = {
             'hostname': hostname,