resourceloader: Don't add "&*" query parameter to load.php urls
Follows-up r88883 (8dab43f703). The IEUrlExtension library only considers the
query string if the base path has no extension (or if the dot is urlencoded).
Neither of which is the case for load.php urls.
If the server doesn't expose undecoded request URIs (per IEUrlExtension)
then it will look in the query string always. However even then it is
only an issue if the last query parameter in the url contains a dot,
which is very unlikely for load.php (they typically end in 'skin' or
'version' which don't contain plain dots).