Use OK Http client bean instead of instance variable. Fixes #46

spring-cloud-openfeign-core/src/main/java/org/springframework/cloud/openfeign/FeignAutoConfiguration.java

@@ -202,8 +202,8 @@ public class FeignAutoConfiguration {
 
 		@Bean
 		@ConditionalOnMissingBean(Client.class)
-		public Client feignClient() {
+		public Client feignClient(okhttp3.OkHttpClient client) {
-			return new OkHttpClient(this.okHttpClient);
+			return new OkHttpClient(client);
 		}
 	}