lib: use traditional yacc empty statement

%empty was added in bison 2.7.1, which seems to not be available on some
of the BSDs by default.

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/lib/command_parse.y b/lib/command_parse.y
index 6348643b8b..e381507cc3 100644
--- a/lib/command_parse.y
+++ b/lib/command_parse.y
@@ -198,7 +198,7 @@ sentence_root: WORD
 ;
 
 cmd_token_seq:
-  %empty
+  /* empty */
 | cmd_token_seq cmd_token
 ;