QSSTV fix source

I did confirm with developer this is his source

functions/additional.function

@@ -481,19 +481,17 @@ QSSTV() {
 
 	cd ${BUILDDIR} || return
 
-	TAR=$(curl -s http://users.telenet.be/on4qz/qsstv/downloads/ | grep tar.gz | sed 's/.*href="//' | sed 's/">.*$//' | tail -1)
-	wget --tries 2 --connect-timeout=60 http://users.telenet.be/on4qz/qsstv/downloads/$TAR
-	tar -xvzf $TAR
-	SSTVTAR=$(ls -d */ | grep qss)
-	cd $SSTVTAR || return
+	git clone https://github.com/ON4QZ/QSSTV
+	cd QSSTV/src || return
+
 	qmake
 	make
 	sudo make install
 	sudo make clean
 	cd ${BUILDDIR} || return
-	rm *.gz
+
 	mkdir -p /usr/local/share/pixmaps/
-	sudo cp ${BUILDDIR}/${SSTVTAR}/icons/qsstv.png /usr/local/share/pixmaps/
+	sudo cp ${BUILDDIR}/QSSTV/src/icons/qsstv.png /usr/local/share/pixmaps/
 
 cat >qsstv.desktop <<EOF
 [Desktop Entry]