Work around workflow blocking error with duplicate "master" refs in "Land Revision"
Until that can happen, provide a workaround for the biggest immediate issue, where multiple copies of a ref cursor can cause executeOne() to throw, since it expects a single result. In practice, these copies are always identical so we can just pick the first one.
This will get cleaned up once T11823 is fixed properly.
Forced the table into a duplicate/ambiguous state, reproduced a similar-looking error:
Applied the patch, got the "Land" to work as expected:
Reviewed By: amckinley
Maniphest Tasks: T11823
Differential Revision: https://secure.phabricator.com/D18599