Downcase "Wincrypt.h"

This is consistent with how we refer to other Windows include files, and
prevents a failure when cross-compiling on a system with case sensitive
file names.

src/port/pg_strong_random.c

@@ -28,7 +28,7 @@
 #include <openssl/rand.h>
 #endif
 #ifdef WIN32
-#include <Wincrypt.h>
+#include <wincrypt.h>
 #endif
 
 #ifdef WIN32