Fix upgrade tmp

[Salamandar]

Problem

ynh_smart_mktemp min_size=300 is not enough for me. some apps are huge, my current install_dir is 1.6GB, and my /tmp is 1.4GB free only.

Solution

The best way to ensure there is enough disk space is to use a temporary directory just next to the install_dir.

PR Status

• [ ] Code finished and ready to be reviewed/tested
• [ ] The fix/enhancement were manually tested (if applicable)

Automatic tests

Automatic tests can be triggered on https://ci-apps-dev.yunohost.org/ after creating the PR, by commenting "!testme", "!gogogadgetoci" or "By the power of systemd, I invoke The Great App CI to test this Pull Request!". (N.B. : for this to work you need to be a member of the Yunohost-Apps organization)

[ericgaspar]

!testme

[yunohost-bot]

:rocket: