swupdate: Lua 5.1 / LuaJIT are not supported

Before commit 87b6ac1478821351c92f7ca1c3154550e4713b28 support for Lua
was always disabled by the default config file:

```
CONFIG_LUA is not set
```

The commit removed this setting and Lua support is now enabled if a Lua
interpreter is enabled. As the swupdate build system uses pkg-config to
check for the lua library by default (LUAPKG="lua") this throws a lot of
undefined referenced in case LuaJIT is uses as Lua interpreter, e.g.:

```
corelib/lib.a(lua_interface.o): In function `l_info':
lua_interface.c:(.text.l_info+0x14): undefined reference to `luaL_checklstring'
```

In addition, since version 2017.07, Lua 5.1 really isn't supported any
more (before this version, it was only unsupported if the option
CONFIG_HANDLER_IN_LUA was set).  Therefore, remove support for Lua 5.1
and LuaJIT in the swupdate package for now until upstream might fix
this issue.

Reported upstream:
https://groups.google.com/forum/#!topic/swupdate/WAm8npAOd6o

Fixes:
http://autobuild.buildroot.net/results/df2/df2a71efe5af52d7b8721a355c49934b1be197a3/
http://autobuild.buildroot.net/results/400/4006225c8a47eb0b56399c83bd6d00406a0f62c2/
http://autobuild.buildroot.net/results/098/098f9d6cd905359adac4fb15e1d54c5022757325/
http://autobuild.buildroot.net/results/e5f/e5f6f99d96d9c661454335e7f931a03c3ae6a9e2/
http://autobuild.buildroot.net/results/f3a/f3a0abe8d5e35c85da40d20dab260c28506a0d4c/

Signed-off-by: Jörg Krause <joerg.krause@embedded.rocks>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

package/swupdate/Config.in

@@ -4,7 +4,7 @@ config BR2_PACKAGE_SWUPDATE
 	depends on BR2_USE_MMU # fork()
 	# swupdate requires a parser and uses libconfig as default
 	select BR2_PACKAGE_LIBCONFIG if !BR2_PACKAGE_JSON_C && \
-		!BR2_PACKAGE_HAS_LUAINTERPRETER
+		!BR2_PACKAGE_LUA_5_2 && !BR2_PACKAGE_LUA_5_3
 	help
 	  swupdate provides a reliable way to update the software on an
 	  embedded system.
@@ -19,11 +19,8 @@ config BR2_PACKAGE_SWUPDATE
 	  use your own modified configuration, you have to select the
 	  necessary packages manually:
 
-	  * Select BR2_PACKAGE_LUA or BR2_PACKAGE_LUAJIT if you want
+	  * Select BR2_PACKAGE_LUA_5_2 or BR2_PACKAGE_LUA_5_3 if you want
 	    to have Lua support.
-	    CONFIG_HANDLER_IN_LUA is not supported in LuaJIT or Lua 5.1.
-	    Note that for LuaJIT support, you need to set
-	    CONFIG_LUAVERSION="jit-5.1".
 	  * Select BR2_LIBCURL if you want to use the download feature.
 	  * Select BR2_PACKAGE_OPENSSL is you want to add encryption support.
 	  * Select BR2_PACKAGE_MTD if you want to use swupdate with UBI

package/swupdate/swupdate.mk

@@ -39,8 +39,8 @@ else
 SWUPDATE_MAKE_ENV += HAVE_LIBCURL=n
 endif
 
-ifeq ($(BR2_PACKAGE_HAS_LUAINTERPRETER),y)
-SWUPDATE_DEPENDENCIES += luainterpreter host-pkgconf
+ifeq ($(BR2_PACKAGE_LUA_5_2)$(BR2_PACKAGE_LUA_5_3),y)
+SWUPDATE_DEPENDENCIES += lua host-pkgconf
 SWUPDATE_MAKE_ENV += HAVE_LUA=y
 else
 SWUPDATE_MAKE_ENV += HAVE_LUA=n