Back out 47fb16f8fb6a (bug 968645) to reenable test_input_sanitization.html on b2g desktop now that we've switched back to m1.medium slaves

testing/mochitest/b2g-desktop.json

@@ -173,7 +173,6 @@
 
     "content/html/content/test/forms/test_input_file_picker.html":"5 failures out of 139 and timing out, bug 901581",
     "content/html/content/test/forms/test_validation.html":"374 total, bug 901848, no keygen support",
-    "content/html/content/test/forms/test_input_sanitization.html":"times out",
 
     "content/html/content/test/test_bug430351.html":"13 failing out of 700, not focusable iframes? bug 902207",