fix: add error message + instruction to detach team from vacancy

Fixes #10.

Signed-off-by: miguel456 <me@nogueira.codes>

app/Http/Controllers/VacancyController.php

@@ -153,10 +153,18 @@ class VacancyController extends Controller
     public function delete(Request $request, Vacancy $vacancy)
     {
         $this->authorize('delete', $vacancy);
+
+        if ($vacancy->teams->isEmpty()) {
+
             $vacancy->delete();
 
             return redirect()
                 ->back()
                 ->with('success', __('Vacancy deleted. All applications associated with it are now gone too.'));
         }
+
+        return redirect()
+            ->back()
+            ->with('error', __('Please detach any teams that may be using this vacancy first.'));
+    }
 }