Backport: Avoid using obsolete indent-relative-maybe

Backport: Avoid using obsolete indent-relative-maybe

* lisp/electric.el (electric-indent-functions-without-reindent):
* lisp/indent.el (indent-according-to-mode): Check for
indent-relative-first-indent-point in addition to its obsolete alias
indent-relative-maybe.
* lisp/obsolete/vi.el (vi-com-map): Use
indent-relative-first-indent-point in place of its obsolete alias
indent-relative-maybe.

(cherry picked from commit 0e468a620458fecd003c396050aa6deb722982c1)