Revert "Nudge icomplete-mode a little closer to fido-mode"

Fixes bug#38131.

This is not the best way to have fido-mdoe emulate that particular bit
of ido-mode.

This reverts commit 5761a1a3.
1 job for master in 26 minutes and 3 seconds (queued for 3 seconds)
Status Job ID Name Coverage
failed #4160


Name Stage Failure
test-all Test
Makefile:152: recipe for target 'cus-load.el' failed
make[2]: *** [cus-load.el] Error 255
make[2]: Leaving directory '/builds/emacs/emacs/lisp'
Makefile:411: recipe for target 'lisp' failed
make[1]: Leaving directory '/builds/emacs/emacs'
make[1]: *** [lisp] Error 2
make: *** [bootstrap] Error 2
Makefile:1117: recipe for target 'bootstrap' failed
ERROR: Job failed: exit code 1