Statcounter detection was missing cases where script tag was output via document.write (#2243)

E.g. tag code as follows:
```<script type="text/javascript">
var sc_project=12847410; 
var sc_invisible=1; 
var sc_security="cad283e9"; 
var sc_https=1; 
var scJsHost = (("https:" == document.location.protocol) ?
"https://secure." : "http://www.");
document.write("<sc"+"ript type='text/javascript' src='" +
scJsHost+
"statcounter.com/counter/counter.js'></"+"script>");
</script>```