wmllint: fixed a bug in spellchecking caused by Python 3 map()

This bug prevented local spelling words from being added to the spellchecking dictionary, and it was caused by the fact that the map iterator was never iterated.
Replaced with an explicit for cycle.

data/tools/wmllint

@@ -2543,7 +2543,8 @@ def spellcheck(fn, d):
     local_spellings = [w for w in local_spellings if not d.check(w)]
     #if local_spellings:
     #    print("%s: inherited local spellings: %s" % (fn, local_spellings))
-    map(d.add_to_session, local_spellings)
+    for word in local_spellings:
+        d.add_to_session(word)
 
     # Process this individual file
     for nav in WmllintIterator(filename=fn):