net-im/signal-desktop-bin: add start-in-tray for desktop file

Closes: https://github.com/gentoo/gentoo/pull/9430
Package-Manager: Portage-2.3.40, Repoman-2.3.9

net-im/signal-desktop-bin/signal-desktop-bin-1.15.0.ebuild

@@ -6,6 +6,7 @@ EAPI=6
 MY_PN="${PN/-bin/}"
 
 inherit gnome2-utils pax-utils unpacker xdg-utils
+
 DESCRIPTION="Allows you to send and receive messages of Signal Messenger on your computer"
 HOMEPAGE="https://signal.org/
 	https://github.com/WhisperSystems/Signal-Desktop"
@@ -33,6 +34,12 @@ QA_PREBUILT="opt/Signal/signal-desktop
 
 S="${WORKDIR}"
 
+src_prepare(){
+	default
+	sed -e 's|\("/opt/Signal/signal-desktop"\)|\1 --start-in-tray|g' \
+		-i usr/share/applications/signal-desktop.desktop || die
+}
+
 src_install() {
 	insinto /
 	dodoc -r usr/share/doc/signal-desktop/.