[Untested] double the watchdog enforced restart interval

[gordonb3]

lua_pushinteger() treats the value of jive_jiffies() as a signed integer, causing critical MAX_VAL to be reached after 24 days rather than the expected 49 days. By casting the result as a double and calling lua_pushnumber() instead we eliminate the sign change and thereby double the watchdog enforced restart interval.

Signed-off-by: gordonb3 gordon@bosvangennip.nl

[stsichler]

• this may be a good starting point for testing and finding a fix on Lua side, but on the long run, I'd not recommend double as primary datatype for timer values (see "option 1" in my post here and mrw's post here)
• note that in the same file, all timeout checks in process_timers() are broken and need to be fixed as extensively discussed, see here
• note that, in the same file, also jiveL_thread_time() may be a problem, but this needs further investigation

(I know that you've read all this already. I just linked it all in here again for others only staring at this repo)