fix(10i18n): stop leaking shell options

fix(10i18n): stop leaking shell options

The findkeymap function manipulates the shell options and relies on
restoring them using the trap. However, as the function might be called
recursively, each recursive invocation changes the signal handler to its
own. As the recursion is entered with shell options already modified,
the changed trap handler is replaced with restoration to the modified
shell options, not the original ones. This patch wraps the findkeymap
function so that the shellopts are manipulated and restored outside the
recursion.