fix for 'returnCountOnly'

right now, http://koop.dc.esri.com/github/chelm/grunt-geo/forks/FeatureServer/0/query?where=1=1&returnCountOnly=false returns:
`{
 count: 33
}`

checking the value of the parameter which is actually a string resolves the problem.

that being said, parsing all parameters and checking for valid types first would probably be a better fix.  i just don't know how to do that :)