tests/test-issue1438

Fix --blacklist when --jobs > 1 in run_tests.py.

The options parsing logic replaces the options.blacklist initial value,
a list of filenames, with a dict of test names to filenames.  When
runchildren rebuilds the command line to launch child processes the dict
is flattened and provided as a malformed argument when a filename is
expected.

Fix is to remove the blacklist option from child invocations since the
filtering is handled in the parent anyway.

#!/bin/sh
"$TESTDIR/hghave" symlink || exit 80

rm -rf a
hg init a
cd a

ln -s foo link
hg add link
hg ci -mbad link
hg rm link
hg ci -mok
hg diff -g -r 0:1 > bad.patch
hg up 0
hg import --no-commit bad.patch
hg st