fixed none numeric etag

Author: a-brandt

src/main/java/com/arangodb/http/HttpManager.java

@@ -458,7 +458,11 @@ private HttpResponseEntity buildHttpResponseEntity(HttpRequestEntity requestEnti
 		// // TODO etag特殊処理は削除する。
 		Header etagHeader = response.getLastHeader("etag");
 		if (etagHeader != null) {
-			responseEntity.etag = Long.parseLong(etagHeader.getValue().replace("\"", ""));
+			try {
+				responseEntity.etag = Long.parseLong(etagHeader.getValue().replace("\"", ""));
+			} catch (NumberFormatException e) {
+				responseEntity.etag = 0;
+			}
 		}
 		// ヘッダをMapに変換する
 		responseEntity.headers = new TreeMap<String, String>();