adds the conda path as a secure path to sudo.

The regular expression expects that the equals sign has no leading and trailing
spaces after the parameter secure_path. Furthermore it expects that the value
is enclosed in double quotes.

This is the case for the sudoers file in debian based distributions, but the
in centos / redhat based distributions this is not the case. The default value
of the secure_path in centos / redhat based distributions has no double quotes
and leading and trailing spaces.

This change adds optional spaces before and after the space, and makes the
double quotes optional.