fix inconsistent month display and entry.  today is 04012010 not 04002010

Reference: /n/sources/patch/applied/secusermon
Date: Mon Jan  4 21:08:15 CET 2010
Signed-off-by: quanstro@quanstro.net

--- /sys/src/cmd/auth/secstore/secuser.c	Mon Jan  4 21:08:12 2010
+++ /sys/src/cmd/auth/secstore/secuser.c	Mon Jan  4 21:08:10 2010
@@ -123,7 +123,7 @@
 	for(;;){
 		tm = localtime(expsecs);
 		print("expires [DDMMYYYY, default = %2.2d%2.2d%4.4d]: ",
-				tm->mday, tm->mon, tm->year+1900);
+				tm->mday, tm->mon + 1, tm->year+1900);
 		userinput(buf, sizeof(buf));
 		if(strlen(buf) == 0)
 			break;