MT5 translation for homedecor_fences

- Update .luacheckrc to allow signs_lib in globals since the current API
doesn't allow to have it read only (added a FIXME, needs a addition to
signs_lib, ping @VanessaE)

.luacheckrc

@@ -16,7 +16,6 @@ read_globals = {
 	"doors",
 	"stairsplus",
 	"stairs",
-	"signs_lib",
 	"screwdriver",
 	"beds",
 	"technic",
@@ -29,5 +28,6 @@ read_globals = {
 
 globals = {
 	"armor",
+	"signs_lib",
 }