FIX: lost interceptors (alternative fix for #2782)

Author: hosuaby

core/src/main/java/feign/BaseBuilder.java

@@ -262,7 +262,7 @@ B enrich() {
                 }
               });
 
-      B enrichedBuilder = (B) clone.clone();
+      B enrichedBuilder = clone;
 
       for (final Capability capability : capabilities) {
         enrichedBuilder = capability.beforeBuild(enrichedBuilder);

oauth2/src/main/java/feign/auth/oauth2/OAuth2Authentication.java

@@ -92,11 +92,12 @@ public <B extends BaseBuilder<B, T>, T> B beforeBuild(final B baseBuilder) {
 
     idpClient = new OAuth2IDPClient(httpClient, httpOptions, jsonDecoder);
 
-    return baseBuilder
-        .requestInterceptor(new AuthenticationInterceptor())
-        .retryer(new UnauthorizedRetryer())
-        .errorDecoder(UnauthorizedErrorDecoder.INSTANCE)
-        .logger(this.logger);
+    baseBuilder.requestInterceptor(new AuthenticationInterceptor());
+    baseBuilder.retryer(new UnauthorizedRetryer());
+    baseBuilder.errorDecoder(UnauthorizedErrorDecoder.INSTANCE);
+    baseBuilder.logger(this.logger);
+
+    return baseBuilder;
   }
 
   private synchronized String getAccessToken() {