Fix #51: Catching SIGSEGV not needed anymore

This patch fixes issue #51 by reverting b4b63d3, which is not needed
anymore since service callbacks have been removed from Finit3.

The `sig_unblock()` function, called for each forked off child, should
now be balanced with caught signals.

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

service.c

@@ -185,7 +185,7 @@ static int service_start(svc_t *svc)
 	/* Declare we're waiting for svc to create its pidfile */
 	svc_starting(svc);
 
-	/* Block sigchild while forking.  */
+	/* Block SIGCHLD while forking.  */
 	sigemptyset(&nmask);
 	sigaddset(&nmask, SIGCHLD);
 	sigprocmask(SIG_BLOCK, &nmask, &omask);