When performing a fetch, sometimes tracking branches no longer present on remote(s) are not pruned despite the user selecting to do so. Prioritized initially as major due to this causing team members to inadvertently necro and build upon intentionally removed branches.

Steps to reproduce:
1) Perform a fetch using the Fetch icon on the main/top button bar
2) Check all 3 boxes
3) Observe that a branch which is known to have been removed from the remote still appears under the remote tracking branches within SourceTree.

Solution:
--prune does not invoke pruning of tracking branches when used at the same time as --tags. Fetch new tags and prune branches via separate commands unless some other arrangement of flags provides the intended result. When not selecting the checkbox to fetch new tags, the prune appears to work. Note: perhaps preserving the prior 'fetch all tags' checkbox state between calls may now be possible without causing issues.