jenkinsfile: ignoer submodules errors

Change-Id: Id3e23e3273f95d522ad6b6af4314a76c508682d1

Jenkinsfile

@@ -140,7 +140,7 @@ See https://wiki.savoirfairelinux.com/wiki/Jenkins.jami.net#Configuration_client
                       git reset --hard origin/${params.CHANNEL}
                       git status
                       # Submodules are generally not managed by merging
-                      git merge -X theirs --no-commit FETCH_HEAD
+                      git merge -X theirs --no-commit FETCH_HEAD || true
                       git status
                       git checkout FETCH_HEAD -- daemon lrc client-qt
                       git status