op.sh: more robust switch for submodules

tools/op.sh

@@ -366,9 +366,11 @@ function op_switch() {
   BRANCH="$1"
 
   git config --replace-all remote.origin.fetch "+refs/heads/*:refs/remotes/origin/*"
+  git submodule deinit --all --force
   git fetch "$REMOTE" "$BRANCH"
   git checkout -f FETCH_HEAD
   git checkout -B "$BRANCH" --track "$REMOTE"/"$BRANCH"
+  git submodule deinit --all --force
   git reset --hard "${REMOTE}/${BRANCH}"
   git clean -df
   git submodule update --init --recursive