disable building with LTO to prevent segfault on startup
When synced to Ubuntu unmodified where LTO is enabled by default, nextcloud-desktop segfaults on startup. Test rebuild in Debian with LTO also results in the same.
Please add optimize=-lto DEB_BUILD_MAINT_OPTION, so wherever the unmodified Debian version is built it runs ok for the user.
This will also ensure that if Debian should move to LTO by default, this issue will not appear again.