conf: turn XTinyproxy into a boolean option

This is what it actually is.

The string value was used in earlier versions to compare
against the uri->authority string. But not as a list of
sites to create an X-Tinyproxy header for, as the tinyproxy.conf
template states...

Michael

src/conf.c

@@ -457,7 +457,7 @@ static HANDLE_FUNC (handle_stathost)
 static HANDLE_FUNC (handle_xtinyproxy)
 {
 #ifdef XTINYPROXY_ENABLE
-        return set_string_arg (&conf->my_domain, line, &match[2]);
+        return set_bool_arg (&conf->add_xtinyproxy, line, &match[2]);
 #else
         fprintf (stderr,
                  "XTinyproxy NOT Enabled! Recompile with --enable-xtinyproxy\n");

src/main.h

@@ -62,7 +62,7 @@ struct config_s {
         unsigned int filter_casesensitive;      /* boolean */
 #endif                          /* FILTER_ENABLE */
 #ifdef XTINYPROXY_ENABLE
-        char *my_domain;
+        unsigned int add_xtinyproxy; /* boolean */
 #endif
 #ifdef REVERSE_SUPPORT
         struct reversepath *reversepath_list;

src/reqs.c

@@ -1126,7 +1126,7 @@ process_client_headers (struct conn_s *connptr, hashmap_t hashofheaders)
                 }
         }
 #if defined(XTINYPROXY_ENABLE)
-        if (config.my_domain)
+        if (config.add_xtinyproxy)
                 add_xtinyproxy_header (connptr);
 #endif