node/endpoints: prealloc map in checkModuleAvailability

[rizkyikiw42]

Align to this:

go-ethereum/core/types/transaction.go
Line 633 in 10421ed

633    remove := make(map[common.Hash]struct{}, b.Len())

[rjl493456442]

It's fine. The memory usage of this map is really tiny, we don't care too much for the potential memory reallocation.

[rizkyikiw42]

i see, thanks for your review！