BUILD: mworker: include proxy.h in mworker.c

It's needed for proxies_list and used to be inherited via cfgparse.h.
diff --git a/src/mworker.c b/src/mworker.c
index 4819d16..2cdb028 100644
--- a/src/mworker.c
+++ b/src/mworker.c
@@ -33,7 +33,7 @@
 #include <haproxy/listener.h>
 #include <haproxy/mworker.h>
 #include <haproxy/peers.h>
-#include <haproxy/proxy-t.h>
+#include <haproxy/proxy.h>
 #include <haproxy/signal.h>
 #include <haproxy/stream.h>
 #include <haproxy/stream_interface.h>