[css] fixed warning message
[css] fixed warning message

Change-Id: I1b99f78ad54a01163df805dc614db14e305f9d1a
On-behalf-of: Tatsiana Salikayeva <d2f0da9787c5b75859dfb65eff103409d0a36f87@gmail.com>
Reviewed-on: http://review.couchbase.org/8259
Tested-by: Aliaksey Kandratsenka <340b8e09ca65cd3fc686427fcfed17e87eaf61e2@gmail.com>
Reviewed-by: Aliaksey Kandratsenka <340b8e09ca65cd3fc686427fcfed17e87eaf61e2@gmail.com>

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