read_password needs to store in .localrc.auto if local.conf is used.

when running stack.sh with no passwords in local.conf
read_password() creates localrc and local.conf is ignored

Change-Id: I25ad07569d2b42b190449591d5a01ade8022392c
diff --git a/stack.sh b/stack.sh
index 1a1460d..303541d 100755
--- a/stack.sh
+++ b/stack.sh
@@ -362,7 +362,11 @@
     var=$1; msg=$2
     pw=${!var}
 
-    localrc=$TOP_DIR/localrc
+    if [[ -f $RC_DIR/localrc ]]; then
+        localrc=$TOP_DIR/localrc
+    else
+        localrc=$TOP_DIR/.localrc.auto
+    fi
 
     # If the password is not defined yet, proceed to prompt user for a password.
     if [ ! $pw ]; then