Sequencer: Fix initial canvas display.

sequencer/src/canvas.C

@@ -203,6 +203,8 @@ Canvas::Canvas ( int X, int Y, int W, int H, const char *L ) : Fl_Group( X,Y,W,H
     m.vp = NULL;
 
     end();
+
+    resize( X,Y,W,H);
 }
 
 Canvas::~Canvas ( )