hgweb: remove unused second argument of nextPageVarGet()
nextPageVarGet is a function that's used in ajaxScrollInit() to produce URL of
the next page. Before
f84b01257e06, its second argument previousVal was a
number on /graph pages, and the code was simply adding 60 to it and returning
the resulting value. Now previousVal can only be a string containing changeset
hash, which can't be used the same way (and in fact isn't used in any way).
$ hg init
$ echo 123 > a
$ hg add a
$ hg commit -m "first" a
$ mkdir sub
$ echo 321 > sub/b
$ hg add sub/b
$ hg commit -m "second" sub/b
$ cat sub/b
321
$ hg co 0
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ cat sub/b 2>/dev/null || echo "sub/b not present"
sub/b not present
$ test -d sub || echo "sub not present"
sub not present