Bugfix in Recursive loopback of RenderView inside a SessionSource: fixed

loading and import into main session.

Mixer.h

@@ -109,6 +109,7 @@ protected:
     SourceList candidate_sources_;
     SourceList stash_;
     void insertSource(Source *s, View::Mode m = View::INVALID);
+    void replaceSource(Source *from, Source *to);
 
     void setCurrentSource(SourceList::iterator it);
     SourceList::iterator current_source_;