BUG/MINOR: fix option httplog validation with TCP frontends

Option httplog needs to be checked only once the proxy has been validated,
so that its final mode (tcp/http) can be used. Also we need to check for
httplog before checking the log format, so that we can report a warning
about this specific option and not about the format it implies.
diff --git a/include/types/proxy.h b/include/types/proxy.h
index 622e168..15ed23a 100644
--- a/include/types/proxy.h
+++ b/include/types/proxy.h
@@ -344,6 +344,8 @@
 	int no_options;				/* PR_O_REDISP, PR_O_TRANSP, ... */
 	int no_options2;			/* PR_O2_* */
 
+	char *logformat_string;			/* log format string */
+	char *uniqueid_format_string;		/* unique-id format string */
 	struct {
 		const char *file;		/* file where the section appears */
 		int line;			/* line where the section appears */