add trivial whitespace to error message

git-svn-id: http://svn.igniterealtime.org/svn/repos/openfire/trunk@12223 b35dd754-fafc-0310-a699-88a17e54d16e

src/java/org/jivesoftware/openfire/http/HttpSession.java

@@ -940,7 +940,7 @@ public class HttpSession extends LocalClientSession {
                     failDelivery(delivered.getPackets());
                 }
                 else {
-                    Log.warn("Packets could not be found for session " + getStreamID() + " cannot" +
+                    Log.warn("Packets could not be found for session " + getStreamID() + " cannot " +
                             "be delivered to client");
                 }
             }