Don't install tags that are already installed
Don't install tags that are already installed

The code was installing all the tags it found, even in the cases
the tag was already installed, creating wrong symbols without
type.

8l/scc,k0gaMSX/scc,k0gaMSX/scc,8l/scc,k0gaMSX/kcc,k0gaMSX/scc,k0gaMSX/kcc,8l/scc