SERVER-9191 fix oplog page for dbs that require admin login

[cxmcc]

In oplog page on rest interface, use oplogreader (which had authentication) instead of dbclient (w/o auth) to query oplogs. This fixes the broken oplog page for dbs having a admin account.

https://jira.mongodb.org/browse/SERVER-9191

[cxmcc]

CA signed.

[kangas]

Hi Xiuming,

I see that you have submitted a contributor agreement on 2013-04-05, but your GitHub username was blank. Can you please resubmit the form at http://www.10gen.com/legal/contributor-agreement ? This will help us verify compliance quickly in the future.

I see that Eric Milkie has discussed this issue with you. I will follow up with him to see what the current status is.

[cxmcc]

Hi @kangas , I signed that again few moments ago. Please let me know if it still has issues. Thanks.

[kangas]

@cxmcc I see your updated contributors agreement, it looks good. Thanks!

[kangas]

@xmcc Can you make the changes that Eric suggested? I think these are the only obstacles we are aware of to getting your change included.

[cxmcc]

hi @milkie @kangas sorry for the delay
I did modifications (amended in commit) based on the review:

• rename variable "r" to "reader" (Please let me know if this is better, or if you have a better name in mind?)
• keep lines to 100 characters or less

Thanks

[kangas]

Merged in 23f8257. Thank you for contributing to MongoDB, Xiuming!