ui placeholder not used as default value

[FynnBe]

Occasionally, the ui tagged input, does not return the placeholder value, if the user did not specify a value.

"ui": [{"address": "{id: 'address', type: 'string', placeholder: 'localhost'}"}, ...

_JailedSite.js:706 Uncaught (in promise) Error: Traceback (most recent call last):
  File "/repos/tiktorch\tiktorch\imjoy.py", line 35, in run
    address = socket.gethostbyname(ctx.config.address)
TypeError: gethostbyname() argument 1 must be str, bytes or bytearray, not None
    at JailedSite._decode (_JailedSite.js:706)
    at JailedSite._decode (_JailedSite.js:722)
    at JailedSite._unwrap (_JailedSite.js:763)
    at JailedSite._processMessage (_JailedSite.js:299)
    at v.<anonymous> (_JailedSite.js:68)
    at p.<anonymous> (jailed.js:652)
    at f.<anonymous> (jailed.js:498)
    at f.r.emit (index.js:133)
    at f.onevent (socket.js:278)
    at f.onpacket (socket.js:236)