supervise-daemon: set default respawn-period to 12sec

currently respawn-period defaults to 0, which means if that a
services crashes 10 times (default respawn-max) in a period of 1
year, then supervise-daemon will just stop it completely. which
is very terrible default to say the least.

set it to 12sec by default instead. with the current default
respawn-delay of 0 and respawn-delay-step of 128ms it'd take
roughly ~6 seconds if a service instantly crashes 10 times
(current default respawn-max) in a row.

Author: N-R-K

man/supervise-daemon.8

@@ -153,6 +153,7 @@ Modifies the OOM score adjustment of the daemon.
 .It Fl P , -respawn-period Ar duration
 Sets the duration of a respawn period. See the
 description of --respawn-max and --respawn-delay for more information.
+Default is 12sec.
 .It Fl -respawn-delay-step Ar duration
 Increase the respawn-delay by duration with every retry within respawn-period.
 Default is 128ms.

src/supervise-daemon/supervise-daemon.c

@@ -182,10 +182,10 @@ static int tty_fd = -1;
 #endif
 static pid_t child_pid;
 static int respawn_count = 0;
-static int64_t respawn_delay;
+static int64_t respawn_delay; /* default set inside main() */
 static int64_t respawn_delay_step = TM_MS(128);
 static int64_t respawn_delay_cap = TM_SEC(30);
-static int64_t respawn_period;
+static int64_t respawn_period; /* default set inside main() */
 static int respawn_max = 10;
 static char *fifopath = NULL;
 static int fifo_fd = 0;
@@ -831,7 +831,7 @@ int main(int argc, char **argv)
 	char *str = NULL;
 	char *cmdline = NULL;
 	const char *respawn_delay_str  = "0";
-	const char *respawn_period_str = "0";
+	const char *respawn_period_str = "12sec";
 
 	applet = basename_c(argv[0]);
 	atexit(cleanup);