tdf#91380 add WB_MOVEABLE bit to docking windows

Change-Id: Iab913747180bf1588da2d703069650e3e6916414
Reviewed-on: https://gerrit.libreoffice.org/16445Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

vcl/source/window/builder.cxx

@@ -1045,7 +1045,7 @@ namespace
         else if (sType == "popup-menu")
             nBits |= WB_SYSTEMWINDOW | WB_DIALOGCONTROL | WB_POPUP;
         else if (sType == "dock")
-            nBits |= WB_DOCKABLE;
+            nBits |= WB_DOCKABLE | WB_MOVEABLE;
         else
             nBits |= WB_MOVEABLE;
         return nBits;