wireproto: rephrase the error message for unknown getbundle parameters

In case of an unknown parameter passed to ``getbundle``, the server prints a
message and ignores the parameter. This message was misleadingly prefixed with
"abort: ". The use of "abort: " here is clearly wrong as nothing is actually
aborted and the ``getbundle`` call proceeds without the parameter.

The message is now prefixed with "warning: " and rephrased to make it clearer
that the parameter was simply ignored.

mercurial/wireproto.py

@@ -507,7 +507,7 b' def options(cmd, keys, others):'
             opts[k] = others[k]
             del others[k]
     if others:
-        sys.stderr.write("abort: %s got unexpected arguments %s\n"
+        sys.stderr.write("warning: %s ignored unexpected arguments %s\n"
                          % (cmd, ",".join(others)))
     return opts