Small fix for total download being 0

Author: Ron Radtke

android/src/main/java/com/ReactNativeBlobUtil/ReactNativeBlobUtilReq.java

@@ -197,7 +197,7 @@ public boolean handleMessage(Message msg) {
                             cursor.close();
 
                             ReactNativeBlobUtilProgressConfig reportConfig = getReportProgress(taskId);
-                            float progress = (total != -1) ? written / total : 0;
+                            float progress = (total > 0) ? written / total : 0;
 
                             if (reportConfig != null && reportConfig.shouldReport(progress /* progress */)) {
                                 WritableMap args = Arguments.createMap();