Disable the JRE HTTP cache, if any

We don't want to use the JRE cache when fetching content.

Change-Id: Id76f3e618967c98ed4fbc47a1a2a9e77acbe41ab
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

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

@@ -373,6 +373,7 @@ public class TransportHttp extends HttpTransport implements WalkTransport,
 	final HttpURLConnection httpOpen(final URL u) throws IOException {
 		final Proxy proxy = HttpSupport.proxyFor(proxySelector, u);
 		HttpURLConnection conn = (HttpURLConnection) u.openConnection(proxy);
+		conn.setUseCaches(false);
 		conn.setRequestProperty(HDR_ACCEPT_ENCODING, ENCODING_GZIP);
 		conn.setRequestProperty(HDR_PRAGMA, "no-cache");//$NON-NLS-1$
 		conn.setRequestProperty(HDR_USER_AGENT, userAgent);