Fix compilation failure with glibc 2.26 caused by missing type
declarations:

------
rpc.c: In function ‘nsm_recv_getport’:
rpc.c:469:13: error: ‘UINT16_MAX’ undeclared (first use in this function)
  if (port > UINT16_MAX) {
------

--- a/support/nsm/rpc.c.orig	2016-08-03 20:25:15.000000000 +0200
+++ b/support/nsm/rpc.c	2017-08-26 07:41:11.884000000 +0200
@@ -40,6 +40,7 @@
 
 #include <time.h>
 #include <stdbool.h>
+#include <stdint.h>
 #include <string.h>
 #include <unistd.h>
 #include <fcntl.h>