Improve GetConfigOptionValues function

Hi,

GetConfigOptionValues function extracts the config parameters for the
given variable irrespective of whether it results in noshow or not.
But the parent function show_all_settings ignores the values parameter
if it results in noshow. It's unnecessary to fetch all the values
during noshow. So a return statement in GetConfigOptionValues() when
noshow is set to true is needed. Attached the patch for the same.
Please share your thoughts.

Thanks & Regards,
Nitin Jadhav