component/curl: enable HTTP2

HTTP2 in curl client will allow to test HTTP2 servers.

See: https://curl.haxx.se/docs/http2.html

/reviewed-on !328

component/curl/buildout.cfg

@@ -8,6 +8,7 @@ extends =
   ../pkgconfig/buildout.cfg
   ../xz-utils/buildout.cfg
   ../zlib/buildout.cfg
+  ../nghttp2/buildout.cfg
 parts =
   curl
 
@@ -42,9 +43,9 @@ configure-options =
   --without-libssh2
   --without-librtmp
   --without-libidn
-  --without-nghttp2
+  --with-nghttp2=${nghttp2:location}
 
 environment =
   PATH=${perl:location}/bin:${pkgconfig:location}/bin:${xz-utils:location}/bin:%(PATH)s
-  PKG_CONFIG_PATH=${openssl:location}/lib/pkgconfig
-  LDFLAGS=-Wl,-rpath=${zlib:location}/lib -Wl,-rpath=${openssl:location}/lib
+  PKG_CONFIG_PATH=${openssl:location}/lib/pkgconfig:${nghttp2:location}/lib/pkgconfig
+  LDFLAGS=-Wl,-rpath=${zlib:location}/lib -Wl,-rpath=${openssl:location}/lib -Wl,-rpath=${nghttp2:location}/lib