title: How to change SocialAuthenticationFilter.filterProcessesUrl when using SpringSocialConfigurer?
body: <p>The Spring Social <code>SocialAuthenticationFilter</code> processes the url <code>/auth</code>. How can I change this url?<br>
  There is a method <code>SocialAuthenticationFilter.setFilterProcessesUrl(String filterProcessesUrl)</code>. How can I access the <code>SocialAuthenticationFilter</code> object to use this method? (I use <code>SpringSocialConfigurer</code>, which automatically adds <code>SocialAuthenticationFilter</code> to the chain.)</p>