Re-enable mlbshop after external fix of checkbox issue

Verified fix and test case works fine again now.

Bug: 1069615
Change-Id: I3ce9b1419d765bcb71210b2453df63b2d913b81f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2152994
Auto-Submit: Ian Struiksma <ianstruiksma@google.com>
Reviewed-by: Sven Zheng <svenzheng@chromium.org>
Commit-Queue: Sven Zheng <svenzheng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#759840}

chrome/test/data/autofill/captured_sites/testcases.json

@@ -117,7 +117,7 @@
     { "site_name": "mango" },
     { "site_name": "mapsofindia" },
     { "site_name": "mercurypay" },
-    { "site_name": "mlbshop", "disabled":true, "bug_number":1069615 },
+    { "site_name": "mlbshop" },
     { "site_name": "modcloth" },
     { "site_name": "moma" },
     { "site_name": "monoprice" },