Replaced "except for by" with "except by"

Author: eyherabh

book/02-git-basics/sections/tagging.asc

@@ -242,7 +242,7 @@ Previous HEAD position was 99ada87... Merge pull request #89 from schacon/append
 HEAD is now at df3f601... add atlas.json and cover image
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-In ``detached HEAD'' state, if you make changes and then create a commit, the tag will stay the same, but your new commit won't belong to any branch and will be unreachable, except for by the exact commit hash. Thus, if you need to make changes -- say you're fixing a bug on an older version, for instance -- you will generally want to create a branch:
+In ``detached HEAD'' state, if you make changes and then create a commit, the tag will stay the same, but your new commit won't belong to any branch and will be unreachable, except by the exact commit hash. Thus, if you need to make changes -- say you're fixing a bug on an older version, for instance -- you will generally want to create a branch:
 
 [source,console]
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