NullPointerException in PermissionManager when null entity is passed

In theory null should not be passed as an entity (issue or project) to the hasPermission methods. However, some bad code sometimes does this.

in this case, instead of allowing the code in hasPermission method to throw the real NullPointerException with a proper error message, the NullPointerException is dropped as another NullPointerException is generated in the finally block which is meant to generate method call timing statistics.

Need to ensure that line 126 in AbstractPermissionManager caters for null projectOrIssue.