increase syslog message limit from 256 to 1024

this addresses alpine linux issue #3692 and brings the syslog message
length limit in alignment with uclibc's implementation.

src/misc/syslog.c

@@ -81,7 +81,7 @@ static void _vsyslog(int priority, const char *message, va_list ap)
 	char timebuf[16];
 	time_t now;
 	struct tm tm;
-	char buf[256];
+	char buf[1024];
 	int errno_save = errno;
 	int pid;
 	int l, l2;