Update SpringSecurity.java

[Kappa97]

--fix for first log in

[DAVIDSS79]

HttpSessionRequestCache requestCache = new HttpSessionRequestCache();
requestCache.setMatchingRequestParameterName("continue");

    http.csrf().disable()
            .authorizeHttpRequests((authorize) ->
                    authorize.requestMatchers("/register/**").permitAll()
                            .requestMatchers("/index").permitAll()
                            .requestMatchers("/users").hasRole("ADMIN")
            ).formLogin(
                    form -> form
                            .loginPage("/login")
                            .loginProcessingUrl("/login")
                            .defaultSuccessUrl("/users") 
                            .defaultSuccessUrl("/users", true)                                
                            .permitAll()
            ).logout(
                    logout -> logout
                            .logoutRequestMatcher(new AntPathRequestMatcher("/logout"))
                            .permitAll()
            ).requestCache((cache) -> cache
            .requestCache(requestCache)
            );        
    return http.build();