CLEANUP: include: remove unused mux_pt.h

It used to be needed to export mux_pt_ops when it was the only way to
detect a mux but that's no longer the case.
diff --git a/include/proto/mux_pt.h b/include/proto/mux_pt.h
deleted file mode 100644
index d61305a..0000000
--- a/include/proto/mux_pt.h
+++ /dev/null
@@ -1,37 +0,0 @@
-/*
- * include/proto/mux_pt.h
- * This file contains the pass-though mux function prototypes
- *
- * Copyright (C) 2017 Willy Tarreau - w@1wt.eu
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation, version 2.1
- * exclusively.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
- */
-
-#ifndef _PROTO_MUX_PT_H
-#define _PROTO_MUX_PT_H
-
-#include <haproxy/api.h>
-#include <types/connection.h>
-
-extern const struct mux_ops mux_pt_ops;
-
-#endif /* _PROTO_MUX_PT_H */
-
-/*
- * Local variables:
- *  c-indent-level: 8
- *  c-basic-offset: 8
- * End:
- */
diff --git a/src/backend.c b/src/backend.c
index 8567135..f8b8ddb 100644
--- a/src/backend.c
+++ b/src/backend.c
@@ -43,7 +43,6 @@
 #include <proto/lb_fwrr.h>
 #include <proto/lb_map.h>
 #include <proto/log.h>
-#include <proto/mux_pt.h>
 #include <proto/payload.h>
 #include <haproxy/protocol.h>
 #include <proto/http_ana.h>
diff --git a/src/checks.c b/src/checks.c
index 314a1b2..2e4c4b0 100644
--- a/src/checks.c
+++ b/src/checks.c
@@ -55,7 +55,6 @@
 #include <proto/stats.h>
 #include <haproxy/fd.h>
 #include <proto/log.h>
-#include <proto/mux_pt.h>
 #include <proto/queue.h>
 #include <haproxy/port_range.h>
 #include <proto/proto_tcp.h>
diff --git a/src/peers.c b/src/peers.c
index 6253604..899d5b4 100644
--- a/src/peers.c
+++ b/src/peers.c
@@ -40,7 +40,6 @@
 #include <proto/cli.h>
 #include <haproxy/fd.h>
 #include <proto/log.h>
-#include <proto/mux_pt.h>
 #include <proto/peers.h>
 #include <proto/proxy.h>
 #include <proto/session.h>
diff --git a/src/stream_interface.c b/src/stream_interface.c
index 02d20a0..bd991de 100644
--- a/src/stream_interface.c
+++ b/src/stream_interface.c
@@ -29,7 +29,6 @@
 #include <proto/applet.h>
 #include <proto/channel.h>
 #include <proto/connection.h>
-#include <proto/mux_pt.h>
 #include <haproxy/pipe.h>
 #include <proto/proxy.h>
 #include <proto/stream.h>