Fix import_wallet_response status (#175)

src/rpc/light_wallet.cpp

@@ -359,7 +359,7 @@ namespace lws
   {
     wire::object(dest,
       WIRE_FIELD_COPY(import_fee),
-      WIRE_FIELD_COPY(status),
+      WIRE_FIELD(status),
       WIRE_FIELD_COPY(new_request),
       WIRE_FIELD_COPY(request_fulfilled)
     );

src/rpc/light_wallet.h

@@ -228,7 +228,7 @@ namespace rpc
   {
     import_response() = delete;
     safe_uint64 import_fee;
-    const char* status;
+    std::string status;
     bool new_request;
     bool request_fulfilled;
   };