fixed couple typos in stats descriptions (courtesy flyspell)
fixed couple typos in stats descriptions (courtesy flyspell)

Change-Id: Ibe5e2930541c25f1bd7ed4f0e6c5034994e937ad
Reviewed-on: http://review.membase.org/6543
Reviewed-by: Bin Cui <ed18693fff32c00e22495f4877a3b901bed09041@gmail.com>
Tested-by: Aliaksey Kandratsenka <340b8e09ca65cd3fc686427fcfed17e87eaf61e2@gmail.com>

membase/ns_server,membase/ns_server,nimishzynga/ns_server,ceejatec/ns_server,vzasade/ns_server,mschoch/ns_server,ceejatec/ns_server,vzasade/ns_server,ceejatec/ns_server,ceejatec/ns_server,membase/ns_server,nimishzynga/ns_server,nimishzynga/ns_server,t3rm1n4l/ns_server,membase/ns_server,pavel-blagodov/ns_server,t3rm1n4l/ns_server,daverigby/ns_server,t3rm1n4l/ns_server,membase/ns_server,vzasade/ns_server,mschoch/ns_server,mschoch/ns_server,daverigby/ns_server,ceejatec/ns_server,pavel-blagodov/ns_server,daverigby/ns_server,nimishzynga/ns_server,nimishzynga/ns_server,daverigby/ns_server,t3rm1n4l/ns_server,vzasade/ns_server,nimishzynga/ns_server,mschoch/ns_server,mschoch/ns_server,ceejatec/ns_server,pavel-blagodov/ns_server,membase/ns_server,daverigby/ns_server,t3rm1n4l/ns_server,pavel-blagodov/ns_server,mschoch/ns_server