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/sqlite.tmpl

@@ -1,7 +1,7 @@
 # Template build file for 'sqlite'.
 pkgname=sqlite
 version=3.6.4
-distfiles="http://sqlite.org/$pkgname-$version@.tar.gz"
+distfiles="http://sqlite.org/$pkgname-$version.tar.gz"
 build_style=gnu_configure
 configure_args="--disable-tcl --enable-load-extension --with-readline-inc="
 make_cmd="$XBPS_MASTERDIR/bin/gmake"