signalproxy.h: add missing forward declaration of QIODevice

diff --git a/src/common/signalproxy.h b/src/common/signalproxy.h
index 973ce70..97efc2d 100644 (file)
--- a/src/common/signalproxy.h
+++ b/src/common/signalproxy.h
@@ -27,6 +27,7 @@
 #include "protocol.h"
 
 struct QMetaObject;
+class QIODevice;
 
 class Peer;
 class SyncableObject;