[BUG] server redirection used an uninitialized string.

This might have been introduced with chunk extensions. Note that
the server redirect still does not work because http_get_path()
cannot get the correct path once the request message is in the
HTTP_MSG_DONE state (->som does not point to the start of message
anymore).
diff --git a/src/proto_http.c b/src/proto_http.c
index 17beb0c..5b1ff9f 100644
--- a/src/proto_http.c
+++ b/src/proto_http.c
@@ -674,6 +674,7 @@
 	/* 1: create the response header */
 	rdr.len = strlen(HTTP_302);
 	rdr.str = trash;
+	rdr.size = sizeof(trash);
 	memcpy(rdr.str, HTTP_302, rdr.len);
 
 	/* 2: add the server's prefix */