nodemap: fix a typo in error message

nodemap: fix a typo in error message

Differential Revision: https://phab.mercurial-scm.org/D9934

--- a/mercurial/revlogutils/nodemap.py	Sun Jan 31 23:38:31 2021 +0530
+++ b/mercurial/revlogutils/nodemap.py	Sun Jan 31 23:40:57 2021 +0530
@@ -135,7 +135,7 @@
             "cannot persist nodemap of a filtered changelog"
         )
     if revlog.nodemap_file is None:
-        msg = "calling persist nodemap on a revlog without the feature enableb"
+        msg = "calling persist nodemap on a revlog without the feature enabled"
         raise error.ProgrammingError(msg)
 
     can_incremental = util.safehasattr(revlog.index, "nodemap_data_incremental")