lua: fix broken LUA_VERSION check

/usr/include/lua-5.1/lua.h:19:25: error: token ""Lua 5.1"" is not valid
in preprocessor expressions

CHANGELOG.md

@@ -1,5 +1,11 @@
 # WeeChat ChangeLog
 
+## Version 4.4.1 (under dev)
+
+### Fixed
+
+- lua: fix compilation on Fedora with Lua < 5.2.0 ([#2173](https://github.com/weechat/weechat/issues/2173))
+
 ## Version 4.4.0 (2024-08-17)
 
 ### Changed

src/plugins/lua/weechat-lua.c

@@ -1272,7 +1272,7 @@ weechat_plugin_init (struct t_weechat_plugin *plugin, int argc, char *argv[])
 #if defined(LUA_VERSION_MAJOR) && defined(LUA_VERSION_MINOR)
     weechat_hashtable_set (plugin->variables, "interpreter_version",
                            LUA_VERSION_MAJOR "." LUA_VERSION_MINOR);
-#elif LUA_VERSION
+#elif defined(LUA_VERSION)
     weechat_hashtable_set (plugin->variables, "interpreter_version",
                            LUA_VERSION);
 #else