Removed unused import

Change-Id: I2c55f017fd06bc39f6c76c9af9db14854f36ba2b
Reviewed-on: http://gerrit.dmdirc.com/1012
Automatic-Compile: Gregory Holmes <greg@dmdirc.com>
Reviewed-by: Gregory Holmes <greg@dmdirc.com>

src/com/dmdirc/util/Downloader.java

 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.OutputStream;
-import java.io.UnsupportedEncodingException;
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.net.URLConnection;