fix 曲目原音伴奏返回可用标记

mec-application/src/main/java/com/ym/mec/student/controller/StudentManageController.java

@@ -21,6 +21,7 @@ import com.ym.mec.util.date.DateUtil;
 import com.ym.mec.util.http.HttpUtil;
 import com.ym.mec.util.upload.UploadUtil;
 import io.swagger.annotations.*;
+import org.apache.commons.collections.CollectionUtils;
 import org.apache.commons.lang3.StringUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;