fix compilation with WIN32_LEAN_AND_MEAN

Author: mitjap

common/time_util.h

@@ -32,7 +32,7 @@ either expressed or implied, of the Regents of The University of Michigan.
 #include <time.h>
 
 #ifdef _WIN32
-#include <windows.h>
+#include <Winsock2.h>
 typedef long long suseconds_t;
 #endif