Tweaked automatic invasion planning to use expected next turn meter value instead of current meter value + 1 to ensure successful invasions.

git-svn-id: https://freeorion.svn.sourceforge.net/svnroot/freeorion/trunk@5686 dbd5520b-6a0a-0410-a553-f54834df5b05
Merge remote-tracking branch 'svn-mirror/master'