change to use this.read() relates to github #1577

Author: dghgit

pg/src/main/java/org/bouncycastle/bcpg/BCPGInputStream.java

@@ -151,7 +151,7 @@ public int nextPacketTag()
         {
             try
             {
-                nextB = in.read();
+                nextB = this.read();
             }
             catch (EOFException e)
             {