Fix comment in perltidyrc

Fix the comment for -wtc=m to match the setting.

tests/data/perltidyrc

@@ -6,7 +6,7 @@
 # which can be found at <https://www.eyrie.org/~eagle/software/rra-c-util/>.
 #
 # Written by Russ Allbery <[email protected]>
-# Copyright 2021-2023 Russ Allbery <[email protected]>
+# Copyright 2021-2024 Russ Allbery <[email protected]>
 # Copyright 2012-2013
 #     The Board of Trustees of the Leland Stanford Junior University
 #
@@ -32,7 +32,7 @@
 -nsfs           # no space before semicolon in for (not that I use this form)
 -xci            # improve indentation of nested structures
 -drc            # delete repeated commas in a list
--wtc=m          # add trailing commas to key => value pairs
+-wtc=m          # add trailing commas to all multi-line lists
 -atc            # add trailing commas where needed
 -dtc            # delete trailing commas where needed
 -dwic           # remove commas interfering with welds