Merge two opposite `if` statements in ChoqokTabBar::moveTab()
g++ is apparently not smart enough to realize that one of these two if
statements will be executed no matter what, and throws a
maybe-uninitialized
warning as a result.
That said, with from == to
being handled above, this is clearly the
equivalent of if (A)
followed by if (!A)
, so it makes sense to merge
the both of them.