don't follow stuck windows in deiconify (thanks _markt)

ChangeLog

@@ -3,6 +3,9 @@ Changes for 0.9.16:
 *06/03/27:
    * Fix crash when deiconifying stuck windows with Follow mode (Simon)
      IconButton.cc
+   * Don't Follow stuck windows on deiconify, since they're stuck 
+     (thanks _markt)
+     IconButton.cc
 *06/03/26:
    * Related to external (Simon)
      - Fix title alignment

src/IconButton.cc

@@ -91,7 +91,8 @@ public:
                 break;
             case IconbarTool::FOLLOW:
             default:
-                win.screen().changeWorkspaceID(win.workspaceNumber());
+                if (!win.isStuck())
+                    win.screen().changeWorkspaceID(win.workspaceNumber());
                 break;
             };
             win.raiseAndFocus();