pidgin/pidgin

Remove a parameter from a doc comment on purple_presence_set_idle which was missed

Testing Done:
Had the turtles do their thing. Also verified the warning was gone.

Reviewed at https://reviews.imfreedom.org/r/3159/
syntax: glob
.*.swp
.DS_Store
.flatpak-builder
*.pyc
*~
\#*\#
syntax: regexp
^build(.+)?\/
win32-install-dir(\.release)?
po\/pidgin3\.pot$
^subprojects\/.+\/