Error message is incorrect while querying _stats view in case of single node

Error message is incorrect while querying _stats view in case of single node

Build Tested:
2.5.1-1073-rel

Steps to Repro:
1. Load Data
2. Create View
3. Select Reduce Function _stats
4. Query View

Expected Error Message:

{"error":"error","reason":"reducer failure"}

'

Actual Output:

{"error":"error","reason":"Builtin _stats function requires map values to be numbers"}

Logs:
AssertionError: 'Error occured querying view redview_stats:

{"error":"error","reason":"Builtin _stats function requires map values to be numbers"}

' != 'Error occured querying view redview_stats:

{"error":"error","reason":"reducer failure"}

'

Jenkins Job:
http://qa.hq.northscale.net/job/mac_mountain_lion--50_03--viewquery_viewmerge-P0/17/consoleFull