Fix type for `tty` & `stdin_open`

Signed-off-by: Christophe Labouisse <[email protected]>

compose/config/fields_schema.json

@@ -111,8 +111,8 @@
         "read_only": {"type": "boolean"},
         "restart": {"type": "string"},
         "security_opt": {"type": "array", "items": {"type": "string"}, "uniqueItems": true},
-        "stdin_open": {"type": "string"},
-        "tty": {"type": "string"},
+        "stdin_open": {"type": "boolean"},
+        "tty": {"type": "boolean"},
         "user": {"type": "string"},
         "volumes": {"type": "array", "items": {"type": "string"}, "uniqueItems": true},
         "volume_driver": {"type": "string"},