Fix parsing of query string variables

This space that was added here was added to the parsed value of the
query variable. This broke any comparisons with the value, for example
"myvar=true" resulted in a value of "true ".

This was broken by f796b05e42

The commit also adds unit tests for webutil.getConfigVar() that will
detect problems like this in the future.

vnc_lite.html

@@ -122,7 +122,7 @@
             // Note that we use location.href instead of location.search
             // because Firefox < 53 has a bug w.r.t location.search
             const re = new RegExp('.*[?&]' + name + '=([^&#]*)'),
-                  match = ''.concat(document.location.href, " ", window.location.hash).match(re);
+                  match = ''.concat(document.location.href, window.location.hash).match(re);
 
             if (match) {
                 // We have to decode the URL since want the cleartext value