fdo#53001 disable unlink graphics in image control dialog in base report builder

Embedding graphics in a report builder report is not implemented,
so do not propose it to the user.
It already was not proposed the dialog raised by
"Insert->Picture->From File"
This commit disables embedding the UI when selecting
an image for an already existing Graphic control
(as opposed to inserting a new graphic control).

Change-Id: I107bc59bef8bb29a75140542cc5c2779a37ed113
Signed-off-by: Lionel Elie Mamane <lionel@mamane.lu>

extensions/source/propctrlr/formcomponenthandler.cxx

@@ -2786,7 +2786,7 @@ namespace pcr
         // non-linked images ( e.g. those located in the document
         // stream ) only if document is available
         Reference< XModel > xModel( impl_getContextDocument_nothrow() );
-        bool bHandleNonLink = xModel.is();
+        bool bHandleNonLink = false;
 
         Reference< XFilePickerControlAccess > xController(aFileDlg.GetFilePicker(), UNO_QUERY);
         DBG_ASSERT(xController.is(), "FormComponentPropertyHandler::impl_browseForImage_nothrow: missing the controller interface on the file picker!");