Pull request count in sidebar doesn't update on pjax tab switching (BB-11131)

on page https://bitbucket.org/saleshood/webapp/pull-requests?displaystatus=open

there are three pull requests
a teammate merge one pull request.
click on the open button
there are two pull request listed

expect: the pull request badge number on the pull request icon at the sidebar display number '2'

actual: display number '3'