Use bash features to improve $distfiles parsing.

That means that it's not necessary anymore to use an '@' before the
extract suffix string. yay.

--HG--
extra : convert_revision : 83ce2c783cb917ef59b87eacb0565cfcff277218

templates/jpeg.tmpl

@@ -4,7 +4,7 @@ version=6.0b
 wrksrc=$pkgname-6b
 patch_files="$pkgname-makefile-cfg.diff"
 distfiles="
-ftp://ftp.fu-berlin.de/unix/graphics/jpeg/jpegsrc.v6b@.tar.gz"
+ftp://ftp.fu-berlin.de/unix/graphics/jpeg/jpegsrc.v6b.tar.gz"
 build_style=gnu_configure
 make_install_target="install install-lib"
 configure_args="--enable-shared --enable-static"