update unbound from upstream

external/unbound/libunbound/unbound.h

@@ -356,6 +356,21 @@ int ub_ctx_add_ta(struct ub_ctx* ctx, const char* ta);
  */
 int ub_ctx_add_ta_file(struct ub_ctx* ctx, const char* fname);
 
+/**
+ * Add trust anchor to the given context that is tracked with RFC5011
+ * automated trust anchor maintenance.  The file is written to when the
+ * trust anchor is changed.
+ * Pass the name of a file that was output from eg. unbound-anchor,
+ * or you can start it by providing a trusted DNSKEY or DS record on one
+ * line in the file.
+ * @param ctx: context.
+ *	At this time it is only possible to add trusted keys before the
+ *	first resolve is done.
+ * @param fname: filename of file with trust anchor.
+ * @return 0 if OK, else error.
+ */
+int ub_ctx_add_ta_autr(struct ub_ctx* ctx, const char* fname);
+
 /**
  * Add trust anchors to the given context.
  * Pass the name of a bind-style config file with trusted-keys{}.
@@ -508,7 +523,7 @@ void ub_resolve_free(struct ub_result* result);
 
 /** 
  * Convert error value to a human readable string.
- * @param err: error code from one of the ub_val* functions.
+ * @param err: error code from one of the libunbound functions.
  * @return pointer to constant text string, zero terminated.
  */
 const char* ub_strerror(int err);