LinkFilterDiag: Rename member function to avoid conflict with parent member

親クラスのメンバー関数と名前が重複しているとcppcheckに指摘されたため子クラスのメンバー関数の名前を変更します。

cppcheck 2.12.1のレポート

src/linkfilterpref.h:29:23: warning: The class 'LinkFilterDiag' defines member function with name 'get_url' also defined in its parent class 'PrefDiag'. [duplInheritedMember]
        Glib::ustring get_url() const { return m_entry_url.get_text(); }
                      ^
src/skeleton/prefdiag.h:32:28: note: Parent function 'PrefDiag::get_url'
        const std::string& get_url() const { return m_url; }
                           ^
src/linkfilterpref.h:29:23: note: Derived function 'LinkFilterDiag::get_url'
        Glib::ustring get_url() const { return m_entry_url.get_text(); }
                      ^

JDimproved / JDim

LinkFilterDiag: Rename member function to avoid conflict with parent member #1263