Make sure the MIN() macro is defined.

On MinGW this is not automatically the case, thereby breaking the build.

src/meta.c

@@ -30,6 +30,10 @@
 #include "utils.h"
 #include "xalloc.h"
 
+#ifndef MIN
+#define MIN(x, y) (((x)<(y))?(x):(y))
+#endif
+
 bool send_meta_sptps(void *handle, uint8_t type, const void *buffer, size_t length) {
 	connection_t *c = handle;
 

src/protocol_misc.c

@@ -30,6 +30,10 @@
 #include "utils.h"
 #include "xalloc.h"
 
+#ifndef MIN
+#define MIN(x, y) (((x)<(y))?(x):(y))
+#endif
+
 int maxoutbufsize = 0;
 int mtu_info_interval = 5;
 int udp_info_interval = 5;