Caldav: New workaround for Lightning bug: sleep for 1 second on server unavailable error

git-svn-id: http://svn.code.sf.net/p/davmail/code/trunk@2122 3d1905a2-6b24-0410-a738-b14d5a86fcbd

src/java/davmail/caldav/CaldavConnection.java

@@ -1118,6 +1118,12 @@ public class CaldavConnection extends AbstractConnection {
         } else if (e instanceof HttpPreconditionFailedException) {
             sendErr(HttpStatus.SC_PRECONDITION_FAILED, message);
         } else {
+            // workaround for Lightning bug: sleep for 1 second
+            try {
+                Thread.sleep(1000);
+            } catch (InterruptedException ie) {
+                // ignore
+            }
             sendErr(HttpStatus.SC_SERVICE_UNAVAILABLE, message);
         }
     }