Prevent footprint editor snapping to footprint

Inside the footprint editor, we only want snap points from the base
elements

Fixes https://gitlab.com/kicad/code/kicad/issues/6948

pcbnew/tools/grid_helper.cpp

@@ -43,6 +43,7 @@ using namespace std::placeholders;
 #include <painter.h>
 #include <pcbnew_settings.h>
 #include <tool/tool_manager.h>
+#include <tools/pcb_tool_base.h>
 #include <view/view.h>
 #include <view/view_controls.h>
 
@@ -275,6 +276,13 @@ std::set<BOARD_ITEM*> GRID_HELPER::queryVisible( const BOX2I& aArea,
     {
         BOARD_ITEM* item = static_cast<BOARD_ITEM*>( it.first );
 
+        // If we are in the footprint editor, don't use the footprint itself
+        if( static_cast<PCB_TOOL_BASE*>( m_toolMgr->GetCurrentTool() )->IsFootprintEditor()
+                && item->Type() == PCB_FOOTPRINT_T )
+        {
+            continue;
+        }
+
         // The item must be visible and on an active layer
         if( view->IsVisible( item )
                 && ( !isHighContrast || activeLayers.count( it.second ) )