Fix issue 627: drop incorrect knock on older VCS

Author: Dmitri Tikhonov

book/03-git-branching/sections/basic-branching-and-merging.asc

@@ -173,9 +173,6 @@ This is referred to as a merge commit, and is special in that it has more than o
 .A merge commit
 image::images/basic-merging-2.png[A merge commit.]
 
-It's worth pointing out that Git determines the best common ancestor to use for its merge base; this is different than older tools like CVS or Subversion (before version 1.5), where the developer doing the merge had to figure out the best merge base for themselves.
-This makes merging a heck of a lot easier in Git than in these other systems.
-
 Now that your work is merged in, you have no further need for the `iss53` branch.
 You can close the ticket in your ticket-tracking system, and delete the branch: