Ensure json-rpc interfaces expect double for optional<>.

Author: evoskuil

include/bitcoin/node/interfaces/electrum.hpp

@@ -31,8 +31,8 @@ struct electrum_methods
     static constexpr std::tuple methods
     {
         /// Blockchain methods.
-        method<"blockchain.block.header", number_t, optional<0>>{ "height", "cp_height" },
-        method<"blockchain.block.headers", number_t, number_t, optional<0>>{ "start_height", "count", "cp_height" },
+        method<"blockchain.block.header", number_t, optional<0.0>>{ "height", "cp_height" },
+        method<"blockchain.block.headers", number_t, number_t, optional<0.0>>{ "start_height", "count", "cp_height" },
         method<"blockchain.estimatefee", number_t>{ "number" },
         method<"blockchain.headers.subscribe">{},
         method<"blockchain.relayfee">{},

include/bitcoin/node/interfaces/stratum_v1.hpp

@@ -31,7 +31,7 @@ struct stratum_v1_methods
     static constexpr std::tuple methods
     {
         /// Client requests.
-        method<"mining.subscribe", optional<""_t>, optional<0>>{ "user_agent", "extranonce1_size" },
+        method<"mining.subscribe", optional<""_t>, optional<0.0>>{ "user_agent", "extranonce1_size" },
         method<"mining.authorize", string_t, string_t>{ "username", "password" },
         method<"mining.submit", string_t, string_t, string_t, number_t, string_t>{ "worker_name", "job_id", "extranonce2", "ntime", "nonce" },
         method<"mining.extranonce.subscribe">{},