[BUGFIX] EM: Missing message when installing incompatible extension

If you try to install an extension which depends on a TYPO3 version
lower that the current one the extension isn't installed and any
error is shown. This patch adds the flash message to the queue so it is
visible afterwards.

Resolves: #53461
Releases: 6.2
Change-Id: Id35987db9b4d24e2161863186ebbe5683a7738fc
Reviewed-on: https://review.typo3.org/25307
Reviewed-by: Steffen Ritter
Reviewed-by: Oliver Hader
Reviewed-by: Markus Klein
Tested-by: Markus Klein
Tested-by: Oliver Hader