Update build.sh for switch to newer appimagetool

AppImage/AppImageKit#877 (comment)

Author: Drsheppard01

appimage/build.sh

@@ -78,7 +78,7 @@ chmod +x linuxdeploy-x86_64.AppImage
   -i AppDir/usr/share/icons/hicolor/scalable/apps/conky-logomark-violet.svg \
   -d AppDir/usr/share/applications/conky.desktop
 
-wget https://github.com/AppImage/AppImageKit/releases/download/continuous/appimagetool-x86_64.AppImage
+wget https://github.com/AppImage/appimagetool/releases/download/continuous/appimagetool-x86_64.AppImage
 
 chmod +x appimagetool-x86_64.AppImage