Enable disabled gwtui tests

a283507bccbd408540ae1baf75eb80eb59dce031 disabled EditIteratorTest due
to gwt-test-utils uncompatibility with new GWT 2.6 release.

After fixing the compatibility problem in [1] the tests can be enabled
again.

[1] https://github.com/gwt-test-utils/gwt-test-utils/issues/62

Change-Id: I1f93e6422a1ae60d66f4d8b4abac23b6a1acb4f9
2 files changed