bs1770gain: Remove package

Following discussion in https://github.com/termux/termux-packages/issues/4455 and https://wiki.termux.com/wiki/Dev:Development_Session_42

packages/bs1770gain/build.sh

@@ -1,9 +0,0 @@
-TERMUX_PKG_HOMEPAGE=http://bs1770gain.sourceforge.net/
-TERMUX_PKG_DESCRIPTION="Tool to normalize the loudness of different audio files to the same level"
-TERMUX_PKG_LICENSE="GPL-2.0"
-TERMUX_PKG_VERSION=0.5.2
-TERMUX_PKG_REVISION=1
-TERMUX_PKG_SHA256=73e5738786b57afb89582333ed18206fd2c6d5245717d3b24ace7f7670f9dedc
-TERMUX_PKG_SRCURL=https://downloads.sourceforge.net/project/bs1770gain/bs1770gain/${TERMUX_PKG_VERSION}/bs1770gain-${TERMUX_PKG_VERSION}.tar.gz
-TERMUX_PKG_DEPENDS="ffmpeg, sox"
-