Merge pull request #1378 from CommanderBubble/master

Allow configure to support mingw64

configure.ac

@@ -245,7 +245,7 @@ case "${host_os}" in
         LIBZMQ_CHECK_LANG_FLAG_PREPEND([-Ae])
         AC_CHECK_FUNCS(gethrtime)
         ;;
-    *mingw32*)
+    *mingw*)
         AC_DEFINE(ZMQ_HAVE_WINDOWS, 1, [Have Windows OS])
         AC_DEFINE(ZMQ_HAVE_MINGW32, 1, [Have MinGW32])
         AC_CHECK_HEADERS(windows.h)