fix bug: upload more than 2 files in a single post request will be failed

Author: kailunio

library/src/main/java/com/loopj/android/http/SimpleMultipartEntity.java

@@ -190,7 +190,7 @@ private byte[] createHeader(String key, String filename, String type) {
         }
 
         public long getTotalLength() {
-            long streamLength = file.length();
+            long streamLength = file.length() + CR_LF.length;
             return header.length + streamLength;
         }