remove unneeded import

DumpPublicKey doesn't need a base64 encoder for anything; remove the
import to avoid deprecation warnings.

Change-Id: I7e01b9d77bb66bb99cb3357c886cc4e2e63de6ae
diff --git a/tools/DumpPublicKey.java b/tools/DumpPublicKey.java
index b83a757..12b4f56 100644
--- a/tools/DumpPublicKey.java
+++ b/tools/DumpPublicKey.java
@@ -24,7 +24,6 @@
 import java.security.Key;
 import java.security.PublicKey;
 import java.security.interfaces.RSAPublicKey;
-import sun.misc.BASE64Encoder;
 
 /**
  * Command line tool to extract RSA public keys from X.509 certificates