It's quite obvious, isn't it? You're trying to install something that depends on a library that isn't available in the needed version. You have two possibilities:

a) do not install the package that depends on that library (i.e.: deselect purple-extra-protocols from getting installed)
b) find out where to get that library in a satisfying version from and add the adequate repository or install manually before trying to install purple-extra-protocols.

That's it. No magic, just reading and thinking.