Ensure the compatibility of PySCTP with Python 3.10, through adding a "#define PY_SSIZE_T_CLEAN" preprocessor directive on the top of the "_sctp.c" module file, before including <Python.h>

Author: p1-mmr

_sctp.c

@@ -18,6 +18,9 @@
  * Elvis Pfützenreuter (elvis.pfutzenreuter@{gmail.com,indt.org.br})
  * Copyright (c) 2005 Instituto Nokia de Tecnologia
  */
+
+#define PY_SSIZE_T_CLEAN
+
 #include <Python.h>
 #include <sys/socket.h>
 #include <netinet/in.h>