Removes the double exec that prevented migrations from running

docker/rootfs/etc/s6-overlay/s6-rc.d/init-migrations/run

@@ -10,12 +10,10 @@ cd "${PAPERLESS_SRC_DIR}"
 
 # The whole migrate, with flock, needs to run as the right user
 if [[ -n "${USER_IS_NON_ROOT}" ]]; then
-	exec s6-setlock -n "${data_dir}/migration_lock" python3 manage.py check --tag compatibility paperless
+	python3 manage.py check --tag compatibility paperless
 	exec s6-setlock -n "${data_dir}/migration_lock" python3 manage.py migrate --skip-checks --no-input
 else
-	exec s6-setuidgid paperless \
-		s6-setlock -n "${data_dir}/migration_lock" \
-		python3 manage.py check --tag compatibility paperless
+	s6-setuidgid paperless python3 manage.py check --tag compatibility paperless
 	exec s6-setuidgid paperless \
 		s6-setlock -n "${data_dir}/migration_lock" \
 		python3 manage.py migrate --skip-checks --no-input