fix shiro exp #54

Author: wh1t3p1g

core/src/main/java/ysomap/bullets/objects/ClassWithExistEviClass.java

@@ -101,7 +101,7 @@ public Object doAction(String action, String exception, Object data) throws IOEx
         }else if("read".equals(action) && data instanceof String){
             return FileHelper.fileGetContent((String) data);
         }else if("base64".equals(action) && data instanceof byte[]){
-            return Strings.encodeToString((byte[]) data);
+            return Strings.encodeToBase64String((byte[]) data);
         }else if("gzip".equals(action) && data instanceof byte[]){
             ByteArrayOutputStream outBuf = new ByteArrayOutputStream();
             GZIPOutputStream gzipOutputStream = new GZIPOutputStream(outBuf);