gitweb.js: No need for inProgress in blame_incremental.js
JavaScript is single-threaded, so there is no need for protection
against re-entrancy via inProgress variable.
In particular calls to setInterval handler are stacked if handler
doesn't finish before new interrupt (before new interval). The same
happens with events - they are (hopefully) stacked if even handler
didn't finish work.
Signed-off-by: Jakub Narebski <jnareb@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>