REORG: include: move frontend.h to haproxy/frontend.h
There was no type file for this one, it only contains frontend_accept().
diff --git a/contrib/prometheus-exporter/service-prometheus.c b/contrib/prometheus-exporter/service-prometheus.c
index c64385c..63d6919 100644
--- a/contrib/prometheus-exporter/service-prometheus.c
+++ b/contrib/prometheus-exporter/service-prometheus.c
@@ -16,6 +16,7 @@
#include <haproxy/action-t.h>
#include <haproxy/api.h>
#include <common/cfgparse.h>
+#include <haproxy/frontend.h>
#include <haproxy/http.h>
#include <haproxy/http_htx.h>
#include <haproxy/htx.h>
@@ -27,7 +28,6 @@
#include <proto/applet.h>
#include <proto/backend.h>
#include <haproxy/compression.h>
-#include <proto/frontend.h>
#include <proto/listener.h>
#include <haproxy/pipe.h>
#include <proto/proxy.h>