Allow the "Push" tool bar button to select only the selected branch

First thanks for your great software, i'm a big fan of source tree.

This just a small improvement suggestion.

When you click on the Pull button, by default only the select branch is checked.
When you click on the Push button, by default it select all the local branch.

I really appreciate if the Push can work like the Pull, by default just select the selected branch. Just like when you right click on the branch and do a Push to origin.

Indeed this can maybe just a settings to change the default behaviors.

Thanks for your work

Fred