webkitgtk: Add license hashes

Signed-off-by: Adrian Perez de Castro <aperez@igalia.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
(cherry picked from commit e7f82694cfe98f659ff08b5834e32f8996ca55c5)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/webkitgtk/webkitgtk.hash

@@ -2,3 +2,7 @@
 md5 264a22d7467deae606e42b6eb5dd65af webkitgtk-2.18.3.tar.xz
 sha1 164cad34281ef597a3d4ad214e8037c3ddef4d17 webkitgtk-2.18.3.tar.xz
 sha256 e15420e1616a6f70f321541d467af5ca285bff66b1e0fa68a01df3ccf1b18f9e webkitgtk-2.18.3.tar.xz
+
+# Hashes for license files:
+sha256 0b5d3a7cc325942567373b0ecd757d07c132e0ebd7c97bfc63f7e1a76094edb4 Source/WebCore/LICENSE-APPLE
+sha256 f2b3bd09663381deb99721109d22b47af1213bb43007a8b56a06c6375c8050ce Source/WebCore/LICENSE-LGPL-2.1