Use secp256k1 functions definitions from cpp-ethereum.

iguana/exchanges/CMakeLists.txt

@@ -1,10 +1,6 @@
 include_directories(${CMAKE_CURRENT_SOURCE_DIR})
 set(MM_SOURCES mm.c ../mini-gmp.c ../groestl.c ../segwit_addr.c ../keccak.c)
-if(${CMAKE_SYSTEM_NAME} MATCHES "Windows")
-    set(MM_LIBS ${NANOMSG_LIBRARY} curl pthread libcrypto777 libjpeg libsecp256k1)
-else()
-    set(MM_LIBS ${NANOMSG_LIBRARY} curl pthread libcrypto777 libjpeg libsecp256k1)
-endif()
+set(MM_LIBS ${NANOMSG_LIBRARY} curl pthread libcrypto777 libjpeg libsecp256k1)
 add_executable(marketmaker-testnet ${MM_SOURCES})
 add_executable(marketmaker-mainnet ${MM_SOURCES})
 include_directories(../../crypto777)