Interactive rebase with conflict always aborts

Any time there's a conflict during interactive rebase, the Close button on the output window for the interactive rebase immediately aborts the rebase.

To reproduce:

• Initiate an interactive rebase with a known conflict [0]
• Observe the output window with normal message "error: could not apply..."
• Expected result: click the Close button and be presented with the opportunity to resolve the conflict(s) and continue the rebase
• Actual result: click the Close button and rebase is immediately aborted

See also SRCTREEWIN-2715 which has a slightly misleading description.

[0] Clone https://bitbucket.org/malingo/srctreewin-2912 and attempt to interactive rebase 'other-branch' onto 'master'