Fix vpp built-in version of api_unformat_sw_if_index(...)

Change-Id: I103fe19a1ecbaf3746ec6b957fa1010458cc9fae
Signed-off-by: Dave Barach <dave@barachs.net>
diff --git a/src/vnet/classify/vnet_classify.h b/src/vnet/classify/vnet_classify.h
index d0b896e..2c96663 100644
--- a/src/vnet/classify/vnet_classify.h
+++ b/src/vnet/classify/vnet_classify.h
@@ -502,6 +502,7 @@
 unformat_function_t unformat_ip4_match;
 unformat_function_t unformat_ip6_match;
 unformat_function_t unformat_l3_match;
+unformat_function_t unformat_l4_match;
 unformat_function_t unformat_vlan_tag;
 unformat_function_t unformat_l2_match;
 unformat_function_t unformat_classify_match;