Fix branch variable name in translation workflow

Author: webknjaz

.github/workflows/translation.yml

@@ -35,7 +35,7 @@ jobs:
           '+refs/heads/${{
               env.I18N_BRANCH
           }}:refs/remotes/origin/${{
-              env.SRC_BRANCH
+              env.I18N_BRANCH
           }}'
 
         git checkout -B '${{ env.I18N_BRANCH }}' \