[BUGFIX] felogin plugin still uses old class name in TypoScript

FE Login still uses TypoScript with a manual
inclusion of the original file and then the
original class name.

plugin.tx_felogin_pi1 = USER_INT
plugin.tx_felogin_pi1 {
includeLibs = EXT:felogin/pi1/class.tx_felogin_pi1.php
userFunc = tx_felogin_pi1->main
}

This way it is impossible to XCLASS the new
namespaced class "FrontendLoginController"
without also changing the USER_INT userFunc
path.

In order to remove the deprecation, we need to
change the class name - no-brainer.

Resolves: #60063
Releases: 6.3
Change-Id: If09e5a3fdc3317623d5ea1de9af04cb04e606656
Reviewed-on: http://review.typo3.org/31290
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Helmut Hummel <helmut.hummel@typo3.org>
Tested-by: Helmut Hummel <helmut.hummel@typo3.org>