make sure to close gzip stream

Author: gwhalin

src/com/meetup/memcached/MemcachedClient.java

@@ -798,6 +798,7 @@ private boolean set( String cmdname, String key, Object value, Date expiry, Inte
 				GZIPOutputStream gos = new GZIPOutputStream( bos );
 				gos.write( val, 0, val.length );
 				gos.finish();
+				gos.close();
 
 				// store it and set compression flag
 				val = bos.toByteArray();