[tac_plus] Patch: allow escaped double quotes in shared secret

[Jesse Zbikowski]

Hello,

I experienced a problem because I use a mix of special characters in
my tac_plus.conf key.  I always put the key in double-quotes to
protect against spaces and comment characters (#).  However the parser
does not accept an escaped double quote (\") inside a double-quoted
key, although it works fine outside quotes.  Here is my one-line patch
to F4.0.4.15.

--- config.c.orig       2008-08-13 12:56:08.000000000 -0700
+++ config.c    2008-08-13 13:52:58.000000000 -0700
@@ -1515,6 +1515,7 @@

                    /* fall through */
                case '"':
+               case '\\':
                    if (!sym_buf_add(sym_ch)) {
                        sym_code = S_unknown;
                        rch();