new flag in the runcard

Created by: tgiani

After some of the commits of the last few days, if one tries to run one of the runcards for the thoery cov matrix fits which are on the wiki, he/she will get the following error

[ERROR]: Bad configuration encountered: use_thcovmat_if_present was true but no fit was specified.

I ve checked the commits, am I right in thinking that for all the fits we are running right now we should set use_thcovmat_if_present : false ? Thanks