Set modify bit when editing page layout.

Fixes https://gitlab.com/kicad/code/kicad/issues/9891

eeschema/tools/sch_editor_control.cpp

@@ -132,7 +132,9 @@ int SCH_EDITOR_CONTROL::PageSetup( const TOOL_EVENT& aEvent )
     DIALOG_EESCHEMA_PAGE_SETTINGS dlg( m_frame, wxSize( MAX_PAGE_SIZE_MILS, MAX_PAGE_SIZE_MILS ) );
     dlg.SetWksFileName( BASE_SCREEN::m_DrawingSheetFileName );
 
-    if( dlg.ShowModal() != wxID_OK )
+    if( dlg.ShowModal() )
+        m_frame->OnModify();
+    else
         m_frame->RollbackSchematicFromUndo();
 
     return 0;

pagelayout_editor/tools/pl_editor_control.cpp

@@ -100,6 +100,7 @@ int PL_EDITOR_CONTROL::PageSetup( const TOOL_EVENT& aEvent )
     }
     else
     {
+        m_frame->OnModify();
         m_frame->HardRedraw();
     }
     return 0;

pcbnew/tools/board_editor_control.cpp

@@ -338,7 +338,9 @@ int BOARD_EDITOR_CONTROL::PageSettings( const TOOL_EVENT& aEvent )
                                                              MAX_PAGE_SIZE_PCBNEW_MILS ) );
     dlg.SetWksFileName( BASE_SCREEN::m_DrawingSheetFileName );
 
-    if( dlg.ShowModal() != wxID_OK )
+    if( dlg.ShowModal() == wxID_OK )
+        m_frame->OnModify();
+    else
         m_frame->RollbackFromUndo();
 
     return 0;