Remove broken and unnecessary execution guards

Change-Id: If76bf0d0079f14f99f47cef145b1e25381d9edc2
Fix PHP Notice when viewing history of a non-existing thread

PHP Notice: Vector/VectorTemplate.php: Undefined index: href

Bug: 38334
Change-Id: I13785361fb5042062d3b0ec650450b48102f88fb