Merge branch 'jk/ref-filter-colors-fix'

This is the "theoretically more correct" approach of simply
stepping back to the state before plumbing commands started paying
attention to "color.ui" configuration variable.

Let's run with this one.

* jk/ref-filter-colors-fix:
  tag: respect color.ui config
  Revert "color: check color.ui in git_default_config()"
  Revert "t6006: drop "always" color config tests"
  Revert "color: make "always" the same as "auto" in config"

t/t6300-for-each-ref.sh

@@ -442,6 +442,11 @@ test_expect_success '--color can override tty check' '
 	test_cmp expected.color actual
 '
 
+test_expect_success 'color.ui=always does not override tty check' '
+	git -c color.ui=always for-each-ref --format="$color_format" >actual &&
+	test_cmp expected.bare actual
+'
+
 cat >expected <<\EOF
 heads/master
 tags/master