GitHub Project lookups assume there can only be one GitHub Project

[mattreid]

While it is now possible to sync GitHub Project metadata down into Jira, the current implementation assumes that there can only be one GitHub Project to look at, so users can't specify more than one. There's at least one team that is using sync2jira and GHP, and has a subset of their repos which should map to two GitHub Projects to more accurately reflect that either team may pick up issues in there (most of their repos are more clear cut and 1:1). Even if a repo mapped to two GHPs, only one team would work any particular issue, so it would likely be the case that if sync2jira queried both GHPs, it would only find information relevant to that issue in one of them, so there wouldn't be conflicting values to try and determine between. If there were an edge case where more than one GHP returned information, that would be trickier to handle.