Fix whitespace errors to silence luacheck.

Currently all minetest_game PR's are failing travis since the
upstream luacheck now also warns about whitespace issues, and
there are a few of those in the code. This fixes all of them
so we can yet again rely on luacheck.

mods/sethome/init.lua

@@ -43,9 +43,9 @@ end
 sethome.get = function(name)
 	local pos = homepos[name]
 	if pos then
-	 	return vector.new(pos)
+		return vector.new(pos)
 	else
-	 	return nil
+		return nil
 	end
 end