Update net-im/libquotient to 0.6.6 (latest upstream)

libQuotient is a Matrix-client library used by several Matrix
clients in the ports tree. 0.6.6 fixes a crash that can be
triggered remotely. Bump two consumers to make them rebuild.
net-im/spectral isn't bumped because it doesn't see any
development, needs a specific bundled git hash, etc ..

While here mark the old-old name of libQuotient as deprecated;
I don't think it has any consumers.