Schema: reword task input help string

[MetRonnie]

This is misleading:

It doesn't have to be a glob, and if it isn't a glob, then it will match inactive tasks as well as active ones.

cylc-flow/cylc/flow/network/schema.py

Lines 1597 to 1601 in 4b58a6a

	class NamespaceIDGlob(String):
	"""A glob search for an active task or family.
	Can use the wildcard character (`*`), e.g `foo*` might match `foot`.
	"""