Allow error pages as public too (thanks Matt)

Author: jloisel

security-config/src/main/java/com/octoperf/security/config/SecurityConfig.java

@@ -30,7 +30,8 @@
 @FieldDefaults(level = PRIVATE, makeFinal = true)
 class SecurityConfig extends WebSecurityConfigurerAdapter {
   private static final RequestMatcher PUBLIC_URLS = new OrRequestMatcher(
-    new AntPathRequestMatcher("/public/**")
+    new AntPathRequestMatcher("/public/**"),
+    new AntPathRequestMatcher("/error/**")
   );
   private static final RequestMatcher PROTECTED_URLS = new NegatedRequestMatcher(PUBLIC_URLS);