[VPP-1333] crash in ipsec policy cli

[vvalderrv]

DBGvpp# ipsec policy add spd 1 inbound priority 10 action protect sa 20 local-ip-range 192.168.3.1 - 192.168.3.254 remote-ip-range 192.168.4.1 - 192.168.4.254
 
Thread 1 "vpp_main" received signal SIGSEGV, Segmentation fault.
0x00007ffff6d39f74 in ipsec_policy_add_del_command_fn (vm=0x7ffff7b88a40 <vlib_global_main>, input=0x7fffb664bee0, cmd=0x7fffb66b30f8)
    at /home/jtollet/devel/vpp/build-data/../src/vnet/ipsec/ipsec_cli.c:347
347               sa = pool_elt_at_index (im->sad, p1[0]);
(gdb) #0  0x00007ffff6d39f74 in ipsec_policy_add_del_command_fn (vm=0x7ffff7b88a40 <vlib_global_main>, input=0x7fffb664bee0, cmd=0x7fffb66b30f8)
    at /home/jtollet/devel/vpp/build-data/../src/vnet/ipsec/ipsec_cli.c:347
#1  0x00007ffff789ba81 in vlib_cli_dispatch_sub_commands (vm=0x7ffff7b88a40 <vlib_global_main>, cm=0x7ffff7b88c20 <vlib_global_main+480>, input=0x7fffb664bee0, parent_command_index=674)
    at /home/jtollet/devel/vpp/build-data/../src/vlib/cli.c:589
#2  0x00007ffff789b98f in vlib_cli_dispatch_sub_commands (vm=0x7ffff7b88a40 <vlib_global_main>, cm=0x7ffff7b88c20 <vlib_global_main+480>, input=0x7fffb664bee0, parent_command_index=0)
    at /home/jtollet/devel/vpp/build-data/../src/vlib/cli.c:567
#3  0x00007ffff789bd66 in vlib_cli_input (vm=0x7ffff7b88a40 <vlib_global_main>, input=0x7fffb664bee0, function=0x7ffff7939c0d <unix_vlib_cli_output>, function_arg=0)
    at /home/jtollet/devel/vpp/build-data/../src/vlib/cli.c:663
#4  0x00007ffff793f6e7 in unix_cli_process_input (cm=0x7ffff7b887e0 <unix_cli_main>, cli_file_index=0) at /home/jtollet/devel/vpp/build-data/../src/vlib/unix/cli.c:2419
#5  0x00007ffff7940206 in unix_cli_process (vm=0x7ffff7b88a40 <vlib_global_main>, rt=0x7fffb663b000, f=0x0) at /home/jtollet/devel/vpp/build-data/../src/vlib/unix/cli.c:2531
#6  0x00007ffff78da58c in vlib_process_bootstrap (_a=140736244185488) at /home/jtollet/devel/vpp/build-data/../src/vlib/main.c:1231
#7  0x00007ffff63ff650 in clib_calljmp () at /home/jtollet/devel/vpp/build-data/../src/vppinfra/longjmp.S:110
#8  0x00007fffb5d77960 in ?? ()
#9  0x00007ffff78da6b7 in vlib_process_startup (vm=0x0, p=0x7fffb5d779b0, f=0x1887c00a9277a000) at /home/jtollet/devel/vpp/build-data/../src/vlib/main.c:1253
Backtrace stopped: previous frame inner to this frame (corrupt stack?)
(gdb) display im
(gdb) 1: im = (ipsec_main_t *) 0x7ffff786b440 <ipsec_main>
(gdb) display p1
(gdb) 2: p1 = (uword *) 0x0