compilation error src/client.c on hpux

[kinichiro]

try https://github.com/kinichiro/openntpd-portable/tree/build_hpux , and encountered.

  CC       ntpd-client.o
"/usr/include/netinet/ip.h", line 123: error #2020: identifier "n_long" is
          undefined
                n_long  ipt_time[1];
                ^

"/usr/include/netinet/ip.h", line 126: error #2020: identifier "n_long" is
          undefined
                        n_long ipt_time;
                        ^

2 errors detected in the compilation of "client.c".
*** Error exit code 2

[kinichiro]

adding #include <netinet/in_systm.h> in src/ntpd.h resolve compilation error.

...
    25  #include <netinet/in.h>
    26  #include <netinet/in_systm.h>
    27  #include <netinet/ip.h>
    28  #include <arpa/inet.h>
...