merge_tables.pl: improve comment
merge_tables.pl: improve comment

vaidyanathanms/votca.csg,Pallavi-Banerjee21/votca.csg,vaidyanathanms/votca.csg,Pallavi-Banerjee21/votca.csg,Pallavi-Banerjee21/votca.csg,Pallavi-Banerjee21/votca.csg,Pallavi-Banerjee21/votca.csg,vaidyanathanms/votca.csg,vaidyanathanms/votca.csg,Pallavi-Banerjee21/votca.csg,vaidyanathanms/votca.csg