curl: Deprecate idn(1) support and switch to xz tarball

[diizzyy]

libidn(1) is deprecated, add libidn2 support
Switch to xz tarball (smaller size)

Signed-off-by: Daniel Engberg daniel.engberg.lists@pyret.net

[diizzyy]

Compile and run tested: mvebu, WRT3200ACM, OpenWrt Master

Additionally this also fixes curl picking up libidn2 on its own as seen on the buildbots.

Package libcurl is missing dependencies for the following libraries:
libidn2.so.0
Makefile:180: recipe for target '/var/lib/buildbot/slaves/dave-builder/mipsel_24kc/build/sdk/bin/packages/mipsel_24kc/base/libcurl_7.59.0-1_mipsel_24kc.ipk' failed
make[3]: *** [/var/lib/buildbot/slaves/dave-builder/mipsel_24kc/build/sdk/bin/packages/mipsel_24kc/base/libcurl_7.59.0-1_mipsel_24kc.ipk] Error 1

[diizzyy]

Similar to https://patchwork.ozlabs.org/patch/897327/ however that patch doesn't include tarball switch and removal of libidn(1).

[dedeckeh]

Patch has been submitted to master (https://git.openwrt.org/?p=openwrt/openwrt.git;a=commit;h=ed4ac0ed65175230d6a7d3196974e6967b31a074); thanks