Removed the code related to gtk_window_set_icon_list. This code doesn't gain us much and will have even less impact in the future.
Testing Done:
Compiled, ran, verified that calling `gtk_window_set_icon_list(window, NULL);` doesn't crash. I couldn't actually check what a window manager will display because my window manager doesn't show icons.
Reviewed at https://reviews.imfreedom.org/r/77/
# SOME DESCRIPTIVE TITLE.
# Copyright (C) YEAR THE PACKAGE'S COPYRIGHT HOLDER
# This file is distributed under the same license as the PACKAGE package.
#
# Translators:
# Aleksandar Urosevic <urke@users.sourceforge.net>, 2003-2004
# Danilo Segan <dsegan@gmx.net>, 2003-2005
# Filip Miletic <f.miletic@ewi.tudelft.nl>, 2004
# Miloš Popović <gpopac@gmail.com>, 2007-2009
# Nikola Kotur <kotnik@ns-linux.org>, 2006
msgid""
msgstr""
"Project-Id-Version: Pidgin\n"
"Report-Msgid-Bugs-To: \n"
"POT-Creation-Date: 2019-11-10 20:23-0500\n"
"PO-Revision-Date: 2017-09-19 19:26+0000\n"
"Last-Translator: Richard Laager <rlaager@wiktel.com>\n"
"Language-Team: Serbian (Latin) (http://www.transifex.com/pidgin/pidgin/"