[BUGFIX] Do not renumber unique keys in ArrayUtility

In various places throughout the core we are using timestamps followed
by a dot as unique identifiers for array keys (for example the avatar
service is registered that way). The ArrayUtility renumbering function
renumbers these keys on writing configuration, meaning that you cannot
overwrite services registered like that via the configuration manager.

ArrayUtility should not re-order strings containing a number ending with
a single dot.

Change-Id: I7dc1625cfdbab6704df87a8cc06f331d92992d24
Releases: master
Resolves: #82155
Reviewed-on: https://review.typo3.org/53767


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Mathias Brodala <mbrodala@pagemachine.de>
Tested-by: Mathias Brodala <mbrodala@pagemachine.de>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>