Remove unneeded private method find_project

The private method find_project is unneeded, as it just
causes code duplication.

find_project is inherited from ApplicationController. The
allocation to the variable @User from User.current is unneeded,
as it is already inherited from ApplicationController.

Signed-off-by: Martin Abente Lahaye <martin.abente.lahaye@gmail.com>
Simplified variable allocation

Signed-off-by: Martin Abente Lahaye <martin.abente.lahaye@gmail.com>