qt5webkit: correct download URL and hash for 5.6 variant

Commit 06a4975d4bd03 (qt5: bump LTS version to 5.6.3) added an empty hash
for the 5.6.3 variant of qt5webkit, causing failures.

It also forgot to adjust the download URL as the qt5webkit tarballs are no
longer available under official_releases/ like the other submodules, but only
under community_releases/.

Fix both issues.

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
(cherry picked from commit d4a119ccc42f5b93a2e33f99438a86cc5ee1fb00)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/qt5/qt5webkit/qt5webkit.hash

@@ -1,5 +1,5 @@
-# Hash from: http://download.qt.io/snapshots/qt/5.6/5.6.3/latest_src/submodules/qtwebkit-opensource-src-5.6.3.tar.xz.mirrorlist
-sha256  qtwebkit-opensource-src-5.6.3.tar.xz
+# Hash from: http://download.qt.io/community_releases/5.6/5.6.3/qtwebkit-opensource-src-5.6.3.tar.xz.mirrorlist
+sha256  098c6bb25798fbf1b619b540621287787064efc9b586d76ac0ce7e39b87a3896  qtwebkit-opensource-src-5.6.3.tar.xz
 
 # Hash from: http://download.qt.io/official_releases/qt/5.8/5.8.0/submodules/qtwebkit-opensource-src-5.8.0.tar.xz
 sha256 79ae8660086bf92ffb0008b17566270e6477c8fa0daf9bb3ac29404fb5911bec  qtwebkit-opensource-src-5.8.0.tar.xz

package/qt5/qt5webkit/qt5webkit.mk

@@ -5,7 +5,12 @@
 ################################################################################
 
 QT5WEBKIT_VERSION = $(QT5_VERSION)
+ifeq ($(BR2_PACKAGE_QT5_VERSION_LATEST),y)
 QT5WEBKIT_SITE = $(QT5_SNAPSHOTS_SITE)
+else
+QT5WEBKIT_SITE = http://download.qt.io/community_releases/5.6/$(QT5_VERSION)/submodules
+endif
+
 QT5WEBKIT_SOURCE = qtwebkit-opensource-src-$(QT5WEBKIT_VERSION).tar.xz
 QT5WEBKIT_DEPENDENCIES = \
 	host-bison host-flex host-gperf host-python host-ruby \