Documentation: fix statement about rebase.instructionFormat

Since commit 62db524 (rebase -i: generate the script via
rebase--helper, 2017-07-14), the short hash is given in
rebase-todo. Specifying rebase.instructionFormat does not alter this
behavior, contrary to what the documentation implies.

Signed-off-by: Maarten van der Schrieck <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: mvds00

Documentation/config/rebase.txt

@@ -38,7 +38,7 @@ rebase.missingCommitsCheck::
 rebase.instructionFormat::
 	A format string, as specified in linkgit:git-log[1], to be used for the
 	todo list during an interactive rebase.  The format will
-	automatically have the long commit hash prepended to the format.
+	automatically have the commit hash prepended to the format.
 
 rebase.abbreviateCommands::
 	If set to true, `git rebase` will use abbreviated command names in the

Documentation/git-rebase.txt

@@ -523,7 +523,7 @@ See also INCOMPATIBLE OPTIONS below.
 +
 The commit list format can be changed by setting the configuration option
 rebase.instructionFormat.  A customized instruction format will automatically
-have the long commit hash prepended to the format.
+have the commit hash prepended to the format.
 +
 See also INCOMPATIBLE OPTIONS below.