Use author date to be consistent with other tools (fixes #919)

James Moger

2015-09-18 a592329a82d0a85d33abcc63f08df20b79e8e4f7

 src/main/java/com/gitblit/manager/IUserManager.java

@@ -24,6 +24,7 @@
    *
    * @param username
    * @return true if the specified username represents an internal account
     * @since 1.4.0
    */
   boolean isInternalAccount(String username);