* gnu/packages/patches/monero-use-system-miniupnpc.patch: New file.
* gnu/local.mk: Add it.
* gnu/packages/finance.scm (monero): Update to 0.12.3.0.
[source]: Add patch. Remove snippet because miniupnpc, rapidjson
and unbound are no longer bundled in-tree.
[inputs]: Add zeromq, cppzmq, libsodium. Use monero-miniupnpc.
[arguments]: Change build-type to "release".
Signed-off-by: Ludovic Courtès <ludo@gnu.org>