BUILD: proxy: add missing compression-t.h to proxy-t.h
struct comp is used in struct proxy but never declared prior to this
so depending on where proxy.h is included, touching the <comp> field
can break the build.
diff --git a/include/haproxy/proxy-t.h b/include/haproxy/proxy-t.h
index bafe940..2470284 100644
--- a/include/haproxy/proxy-t.h
+++ b/include/haproxy/proxy-t.h
@@ -33,6 +33,7 @@
#include <haproxy/api-t.h>
#include <haproxy/arg-t.h>
#include <haproxy/backend-t.h>
+#include <haproxy/compression-t.h>
#include <haproxy/counters-t.h>
#include <haproxy/freq_ctr-t.h>
#include <haproxy/obj_type-t.h>