discovery: handle deletion of 'wireproto' module
Mercurial commit b4d85bc122bd. deleted the wireproto module and its
contents are now in various other modules, so we can not even do
unchecked imports of it now.
import hghave
@hghave.check("docgraph-ext", "Extension to generate graph from repository")
def docgraph():
try:
import hgext.docgraph
hgext.docgraph.cmdtable # trigger import
except ImportError:
try:
import hgext3rd.docgraph
hgext3rd.docgraph.cmdtable # trigger import
except ImportError:
return False
return True