Issue #17591: Use lowercase filenames when including Windows header files.
Patch by Roumen Petrov.
diff --git a/Objects/exceptions.c b/Objects/exceptions.c
index 6b04700..79bbb8f 100644
--- a/Objects/exceptions.c
+++ b/Objects/exceptions.c
@@ -2327,7 +2327,7 @@
     }
 
 #ifdef MS_WINDOWS
-#include <Winsock2.h>
+#include <winsock2.h>
 /* The following constants were added to errno.h in VS2010 but have
    preferred WSA equivalents. */
 #undef EADDRINUSE