streaming: don't check view building of system tables
streaming: don't check view building of system tables

System tables will never need view building, and, what's more,
are actually used in the process of view build checking.
So, checking whether system tables need a view update path
is simplified to returning 'false'.

scylladb/scylla,avikivity/scylla,scylladb/scylla,scylladb/scylla,avikivity/scylla,avikivity/scylla,scylladb/scylla