Copy isDangling flag when changing label type.

Fixes: lp:1796775
* https://bugs.launchpad.net/kicad/+bug/1796775

eeschema/edit_label.cpp

@@ -203,6 +203,7 @@ void SCH_EDIT_FRAME::OnConvertTextType( wxCommandEvent& aEvent )
     newtext->SetThickness( text->GetThickness() );
     newtext->SetItalic( text->IsItalic() );
     newtext->SetBold( text->IsBold() );
+    newtext->SetIsDangling( text->IsDangling() );
 
     /* Save the new text in undo list if the old text was not itself a "new created text"
      * In this case, the old text is already in undo list as a deleted item.

eeschema/sch_text.h

@@ -176,6 +176,8 @@ public:
 
     virtual bool IsDangling() const override { return m_isDangling; }
 
+    virtual void SetIsDangling( bool aIsDangling ) { m_isDangling = aIsDangling; }
+
     virtual bool IsSelectStateChanged( const wxRect& aRect ) override;
 
     virtual void GetConnectionPoints( std::vector< wxPoint >& aPoints ) const override;