apply patch proposed by 2web to properly remove hidden input set to represent the button used to submit the form, so forms may be properly reused after a post
"""pre 3.6 bw compat"""# pylint: disable-msg=W0614,W0401fromwarningsimportwarnwarn('moved to cubicweb.mttransforms',DeprecationWarning,stacklevel=2)fromcubicweb.mttransformsimport*