Checking for QUrl equality is not all that expensive, so remove hack.

QUrl's operator== used to perform allocations by comparing normalized URLs, but
even then, this code seemingly would not apply: Qt 4's QUrl still has a fast
path for the case where the URLs are empty, the same as this code implemented.

Change-Id: I69e82c848f47f5e5660bd707bfba0ff7343c8a42
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Michael Brasser <michael.brasser@nokia.com>