Use correct moments format for Showing last us time instead of value test (#9923)

Fixes this issue:
PhantomJS 2.1.1 (Mac OS X 0.0.0) SingleStatCtrl showing last us time
instead of value should set formatted value FAILED
	expected '09/17/2017 4:56:37 pm' to equal '09/17/2017 16:56:37 pm'

public/app/plugins/panel/singlestat/specs/singlestat_specs.ts

@@ -104,7 +104,7 @@ describe('SingleStatCtrl', function() {
     });
 
     it('should set formatted value', function() {
-      expect(ctx.data.valueFormatted).to.be(moment(1505634997920).format('MM/DD/YYYY H:mm:ss a'));
+      expect(ctx.data.valueFormatted).to.be(moment(1505634997920).format('MM/DD/YYYY h:mm:ss a'));
     });
   });