message: Add missing source file
diff: @@ -724,6 +724,7 @@ libbitcoin_common_a_SOURCES = \
  cpp-ethereum/libp2p/Session.h \
  cpp-ethereum/libp2p/UDP.h \
  cpp-ethereum/libp2p/UPnP.h \
  + cpp-ethereum/libethashseal/genesis/test/constantinopleFixTest.cpp \
  $(BITCOIN_CORE_H)
  #only added json_spirit so that `make dist` works properly
  