Tweak handling of boost filesystem versions

bitcoin-qt.pro

@@ -256,7 +256,7 @@ windows:RC_FILE = src/qt/res/bitcoin-qt.rc
 macx:HEADERS += src/qt/macdockiconhandler.h
 macx:OBJECTIVE_SOURCES += src/qt/macdockiconhandler.mm
 macx:LIBS += -framework Foundation -framework ApplicationServices -framework AppKit
-macx:DEFINES += MAC_OSX MSG_NOSIGNAL=0 BOOST_FILESYSTEM_VERSION=3
+macx:DEFINES += MAC_OSX MSG_NOSIGNAL=0
 macx:ICON = src/qt/res/icons/bitcoin.icns
 macx:TARGET = "Bitcoin-Qt"
 

src/db.cpp

@@ -51,7 +51,7 @@ static void EnvShutdown(bool fRemoveLogFiles)
         while (it != filesystem::directory_iterator())
         {
             const filesystem::path& p = it->path();
-#if BOOST_FILESYSTEM_VERSION == 3
+#if BOOST_FILESYSTEM_VERSION >= 3
             std::string f = p.filename().generic_string();
 #else
             std::string f = p.filename();