webkit-gtk: update SRCREV

webkit-gtk: update SRCREV

The layout of the repository has changed, so we need to account for that:

* fixed license checksums
* fixed SRC_URI
* fixed SRCREV_FORMAT

PCRE is gone, so no need for the dftables hack anymore

But most importantly, this fixes the crash issues when using javascript (e.g. github.com)

Tested on:

* usrp-e1xx/angstrom-2011.07

Signed-off-by: Koen Kooi <koen@dominion.thruhere.net>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>