Reduce the WebDAV uploader lock timeout from 30 to 10 minutes

As suggested by Curtis Rueden in

	imagej/ImageJ#59 (comment)

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

plugins/uploaders/webdav/src/main/java/imagej/updater/webdav/WebDAVUploader.java

@@ -275,7 +275,7 @@ private String lock(final String path) throws IOException {
 			+ "</owner>"
 			+ "</lockinfo>";
 		try {
-			final HttpURLConnection connection = connect("LOCK", getURL(path, false), xml, "Timeout", "Second-1800");
+			final HttpURLConnection connection = connect("LOCK", getURL(path, false), xml, "Timeout", "Second-600");
 
 			if (connection.getResponseCode() != 200) {
 				throw new IOException("Error obtaining lock for " + path + ": "