hg: use capable instead of capabilities

mercurial/hg.py

@@ -318,7 +318,7 b' def clone(ui, source, dest=None, pull=Fa'
 
             revs = None
             if rev:
-                if 'lookup' not in srcrepo.capabilities:
+                if not srcrepo.capable('lookup'):
                     raise util.Abort(_("src repository does not support "
                                        "revision lookup and so doesn't "
                                        "support clone by revision"))