Email notification includes wrong answer-link to the corresponding conversation

Summary

Message email notification contains a link to answer the received message. The URL in this link is broken (missing &, uc not needed):

Steps to reproduce

Inspect the link in any message notification (personal, group, shop)

What is the current bug behavior?

Link doensn't lead to conversation but start page.

What is the expected correct behavior?

Link brings user directly to the conversation.

Relevant error messages and/or screenshots

Bildschirmfoto_2019-09-26_um_11.15.57

links to: https://foodsharing.de/?page=msg&uc=167256cid=1358767

Possible fixes

https://gitlab.com/foodsharing-dev/foodsharing/blob/master/src/Modules/Message/MessageXhr.php#L128

https://gitlab.com/foodsharing-dev/foodsharing/blob/master/src/Modules/Message/MessageXhr.php#L139

https://gitlab.com/foodsharing-dev/foodsharing/blob/master/src/Modules/Message/MessageXhr.php#L147