Fix link to disable-password-login to docs

app/views/admin/settings/authentication_settings/show.html.erb

@@ -81,10 +81,10 @@ See docs/COPYRIGHT.rdoc for more details.
         <div class="form--field -wide-label">
           <label><b><%= I18n.t :note %>: </b>
             <%=
-              url = 'https://github.com/opf/openproject/blob/dev/doc/CONFIGURATION.md#disable-password-login'
+              url = 'https://docs.openproject.org/installation-and-operations/configuration/#disable-password-login'
 
               explanation = I18n.t :note_password_login_disabled,
-                                   configuration: "<a href=\"#{url}\"> #{I18n.t('label_configuration')}</a>"
+                                   configuration: "<a target=\"_blank\" href=\"#{url}\"> #{I18n.t('label_configuration')}</a>"
 
               explanation.html_safe
             %>