From coverity: set encoding on String to bytes conversion

git-svn-id: http://svn.code.sf.net/p/davmail/code/trunk@2236 3d1905a2-6b24-0410-a738-b14d5a86fcbd

src/java/davmail/AbstractConnection.java

@@ -268,11 +268,11 @@ public class AbstractConnection extends Thread {
         }
     }
 
-    protected String base64Encode(String value) {
-        return new String(new Base64().encode(value.getBytes()));
+    protected String base64Encode(String value) throws UnsupportedEncodingException {
+        return new String(Base64.encodeBase64(value.getBytes("UTF-8")), "UTF-8");
     }
 
-    protected String base64Decode(String value) {
-        return new String(new Base64().decode(value.getBytes()));
+    protected String base64Decode(String value) throws UnsupportedEncodingException {
+        return new String(Base64.decodeBase64(value.getBytes("UTF-8")), "UTF-8");
     }
 }