[TASK] Add autocomplete="off" to Install Tool fields

This patch adds the input attribute autocomplete="off" to form fields
in the Install Tool to prevent auto completion for username and
password fields.

Resolves: #70516
Releases: master
Change-Id: I8f3d72e817e45569050baa89636d46242c13cd2f
Reviewed-on: http://review.typo3.org/43919


Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Reviewed-by: Markus Klein <markus.klein@typo3.org>
Tested-by: Markus Klein <markus.klein@typo3.org>
Reviewed-by: Daniel Goerz <ervaude@gmail.com>
Tested-by: Daniel Goerz <ervaude@gmail.com>
Reviewed-by: Helmut Hummel <helmut.hummel@typo3.org>
Tested-by: Helmut Hummel <helmut.hummel@typo3.org>