define RLIMIT_RTTIME, bump RLIMIT_NLIMITS

This macro exists since Linux 2.6.25 and is defined in glibc since 2011.

include/sys/resource.h

@@ -90,7 +90,8 @@ int prlimit(pid_t, int, const struct rlimit *, struct rlimit *);
 #define RLIMIT_MSGQUEUE 12
 #define RLIMIT_NICE    13
 #define RLIMIT_RTPRIO  14
-#define RLIMIT_NLIMITS 15
+#define RLIMIT_RTTIME  15
+#define RLIMIT_NLIMITS 16
 
 #define RLIM_NLIMITS RLIMIT_NLIMITS