Replace MongoProperties condition for spring-cloud

Replace @ConditionalOnBean(MongoProperties.class) on
MongoDataAutoConfiguration with @EnableConfigurationProperties since
MongoAutoConfiguration will not be applied in a cloud environment.

Fixes gh-1502

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/mongo/MongoDataAutoConfiguration.java

@@ -21,9 +21,9 @@ import java.net.UnknownHostException;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.autoconfigure.AutoConfigureAfter;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
-import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
+import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.dao.DataAccessException;
@@ -54,7 +54,7 @@ import com.mongodb.Mongo;
  */
 @Configuration
 @ConditionalOnClass({ Mongo.class, MongoTemplate.class })
-@ConditionalOnBean(MongoProperties.class)
+@EnableConfigurationProperties(MongoProperties.class)
 @AutoConfigureAfter(MongoAutoConfiguration.class)
 public class MongoDataAutoConfiguration {