Bug 1483901 [wpt PR 12527] - Update wpt metadata, a=testonly

wpt-pr: 12527 wpt-type: metadata
2018-08-16 15:37:56 +00:00 · 2018-08-16 15:37:56 +00:00 · c7054307e7
--- a/testing/web-platform/meta/html/rendering/non-replaced-elements/the-fieldset-element-0/legend-position-relative.html.ini
+++ b/testing/web-platform/meta/html/rendering/non-replaced-elements/the-fieldset-element-0/legend-position-relative.html.ini
@ -0,0 +1,2 @@
+[legend-position-relative.html]
+  expected: FAIL