Source mapping URL should be ignored when sourcemap is disabled

Steps to Reproduce

Disable source map in zk.xml

<client-config>
        <enable-source-map>false</enable-source-map>
</client-config>

and load js with //# sourceMappingURL=xxx.js.map

Current Result

WpdExtendlet try to load source map
and exception occurs when not found

Expected Result

no exception, just ignore

Debug Information

Workaround