OK, I apologize for misconstruing your intention. It's unfortunate how URL schemes work in the first place, but given that reality, there still aren't any acceptable reasons for an application to use one that another application obviously intends to be the exclusive handler of (in this case, indicated by the fact that it is the name of the application itself).
BitBucket's Clone URLs use either https:// or ssh://, just like github or any other service. There isn't any benefit to SmartGit taking over Sourcetree's url scheme, and it breaks Sourcetree. So, please, consider, erm, stopping it...
OK, I apologize for misconstruing your intention. It's unfortunate how URL schemes work in the first place, but given that reality, there still aren't any acceptable reasons for an application to use one that another application obviously intends to be the exclusive handler of (in this case, indicated by the fact that it is the name of the application itself).
In fact, MacOS does not ask what application to use in this case - the browser is launched, and the browser asks if you want to open this URL in SmartGit; no other options are given. https://community.atlassian.com/t5/Sourcetree-questions/Can-t-install-SourceTree-due-to-login-problems-MacOSx-SmartGit/qaq-p/926276
BitBucket's Clone URLs use either https:// or ssh://, just like github or any other service. There isn't any benefit to SmartGit taking over Sourcetree's url scheme, and it breaks Sourcetree. So, please, consider, erm, stopping it...