Compiler warnings when SECURE_NPCTIMEOUT enabled

[jasonch35]

Describe the bug
A clear and concise description of what the bug is.

npc.c: In function 'npc_rr_secure_timeout_timer':
npc.c:308:2: warning: enumeration value 'NPCT_WAIT' not handled in switch [-Wswitch-enum]
  308 |  switch( sd->npc_idle_type ) {
      |  ^~~~~~

To Reproduce
Steps to reproduce the behavior:

1. Enable/Uncomment in /src/config/secure.h
   #define SECURE_NPCTIMEOUT
2. Compile

Expected behavior
A clear and concise description of what you expected to happen.
No warnings

Screenshots
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System specs (please complete the following information):

• OS: debian 11
• latest gcc and make
• Hercules Version v2023.03.08
• Mode: pre-renewal
• Packet version: 20190530