CLEANUP: includes: fix includes for a number of users of fd.h
It appears that fd.h includes a number of unneeded files and was
included from standard.h, and as such served as an intermediary
to provide almost everything to everyone.
By removing its useless includes, a long dependency chain broke
but could easily be fixed.
diff --git a/src/connection.c b/src/connection.c
index cb314ad..748e14e 100644
--- a/src/connection.c
+++ b/src/connection.c
@@ -14,6 +14,7 @@
#include <common/config.h>
#include <proto/connection.h>
+#include <proto/fd.h>
#include <proto/proto_tcp.h>
#include <proto/session.h>
#include <proto/stream_interface.h>