[ENSWEB-1569] handleConfigClick method can be overridden in plugins
[ENSWEB-1569] handleConfigClick method can be overridden in plugins

Ensembl/ensembl-webcode,Ensembl/ensembl-webcode,Ensembl/ensembl-webcode,Ensembl/ensembl-webcode,Ensembl/ensembl-webcode