Update r2s_lienol_from_lean.yml

.github/workflows/r2s_lienol_from_lean.yml

@@ -123,6 +123,7 @@ jobs:
           git remote add upstream https://github.com/Lienol/openwrt && git fetch upstream
           git checkout upstream/dev-lean-lede -b tmp
           git mv README.md README && git commit -m 'undo rename readme for rebasing'
+          git checkout origin/master-v19.07.1
           git rebase adc1a9a3676b8d7be1b48b5aed185a94d8e42728^ --onto tmp -X theirs
           git revert --no-edit f092ca098e80c667b10cdd1dba328506a2673c1d
           git checkout upstream/dev-lean-lede -- feeds.conf.default