[v2.05] Setting "\copyright{none}" leaves new line with single "." in footnote

[alexander-r-block]

When setting \copyright{none} and \copyrightyear{} (i.e., empty), a single "." is still generated in the document. Tested with \documentclass{acmart} and \documentclass[sigconf]{acmart}.

Relevant lines of code seem to be:

acmart/acmart.dtx

Lines 6392 to 6395 in 093bdc7

	\if@printcopyright
	\copyright\ \@copyrightyear\ \@copyrightowner\\
	\else
	\@copyrightyear.\

It seems that a period is printed no matter what, even if \copyright{none} is set.