Silence unchecked conversion warning in TransportSftp

Change-Id: I3dc8e0b483072bdf193ae4190a60d1867ebefd12
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

org.eclipse.jgit/src/org/eclipse/jgit/transport/TransportSftp.java

@@ -227,6 +227,7 @@ public class TransportSftp extends SshTransport implements WalkTransport {
 		Collection<String> getPackNames() throws IOException {
 			final List<String> packs = new ArrayList<String>();
 			try {
+				@SuppressWarnings("unchecked")
 				final Collection<ChannelSftp.LsEntry> list = ftp.ls("pack"); //$NON-NLS-1$
 				final HashMap<String, ChannelSftp.LsEntry> files;
 				final HashMap<String, Integer> mtimes;