patch 8.2.3240: Lua print() does not work properly

Problem:    Lua print() does not work properly.
Solution:   Put back lua_pop().
diff --git a/src/if_lua.c b/src/if_lua.c
index 79fb681..5810401 100644
--- a/src/if_lua.c
+++ b/src/if_lua.c
@@ -1737,6 +1737,7 @@
 	if (i > 1)
 	    luaL_addchar(&b, ' '); // use space instead of tab
 	luaV_addlstring(&b, s, l, 0);
+	lua_pop(L, 1);
     }
     luaL_pushresult(&b);
     if (!got_int)