luvi: fetch uploaded release tarball

Upstream has finally released an uploaded tarball, which is prefered
over cloning the repository from github.

Signed-off-by: Jörg Krause <joerg.krause@embedded.rocks>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/luvi/luvi.hash

@@ -1,2 +1,2 @@
 # Locally calculated
-sha256 6d2297751b4d4023c1fa8b723b6f04e09584c67694958edbfa0d284f384759d5  luvi-v2.7.6.tar.gz
+sha256  ce9a1fb762e61267618ddea9ea129170fd543bb918c382b71cb35985d0024c42  luvi-src-v2.7.6.tar.gz

package/luvi/luvi.mk

@@ -5,8 +5,8 @@
 ################################################################################
 
 LUVI_VERSION = v2.7.6
-LUVI_SITE = git://github.com/luvit/luvi.git
-LUVI_GIT_SUBMODULES = YES
+LUVI_SOURCE = luvi-src-$(LUVI_VERSION).tar.gz
+LUVI_SITE = https://github.com/luvit/luvi/releases/download/$(LUVI_VERSION)
 LUVI_LICENSE = Apache-2.0
 LUVI_LICENSE_FILES = LICENSE.txt
 LUVI_DEPENDENCIES = libuv luajit luv host-luajit