phabricator: make user searches case-insensitive

User names in conduit are case insensitive, but when looking for "FOO"
it would return "foo" instead and we'd think the user didn't exist.  So
lower case both the query and the response when comparing them.

Differential Revision: https://phab.mercurial-scm.org/D5934

hgext/phabricator.py

@@ -450,12 +450,13 b' def createdifferentialrevision(ctx, revi'
 
 def userphids(repo, names):
     """convert user names to PHIDs"""
+    names = [name.lower() for name in names]
     query = {b'constraints': {b'usernames': names}}
     result = callconduit(repo, b'user.search', query)
     # username not found is not an error of the API. So check if we have missed
     # some names here.
     data = result[r'data']
-    resolved = set(entry[r'fields'][r'username'] for entry in data)
+    resolved = set(entry[r'fields'][r'username'].lower() for entry in data)
     unresolved = set(names) - resolved
     if unresolved:
         raise error.Abort(_(b'unknown username: %s')