Update rbx_dom_lua to rojo-rbx/rbx-dom@7b03132 (#775)

Fixes a problem where the MaterialColors Lua encoder would return nothing

plugin/rbx_dom_lua/EncodedValue.lua

@@ -282,6 +282,7 @@ types = {
 					math.round(math.clamp(color.B, 0, 1) * 255)
 				}
 			end
+			return pod
 		end,
 	},