ENH: Clean up gerrit code review system leftovers

Clean up `gerrit` code review system leftovers: `gerrit` was substituted
by `GitHub` early 2018, e.g.
#45

Enough time has elapsed so that all developers have updated their local
configuration.

Author: jhlegarreta

Utilities/GitSetup/config.sample

@@ -14,9 +14,3 @@
 [stage]
 	#url = git://public.kitware.com/stage/Project.git
 	#pushurl = [email protected]:stage/Project.git
-
-[gerrit]
-	#project = Project
-	site = https://review.source.kitware.com
-	# pushurl placeholder "$username" is literal
-	pushurl = [email protected]:Project

Utilities/GitSetup/git-gerrit-push

@@ -8,9 +8,6 @@ git config alias.pr-clean '!git checkout master ; git for-each-ref refs/heads/pr
 # Alias to push the current topic branch to GitHub
 git config alias.review-push "!bash Utilities/GitSetup/git-review-push"
 
-git config alias.gerrit-push \
-  "!bash -c 'echo \\\"git gerrit-push\\\" is deprecated. Please use \\\"git review-push\\\" instead.'"
-
 # Useful alias to see what commits are on the current branch with respect to
 # upstream/master
 git config alias.prepush 'log --graph --stat upstream/master..'

Utilities/GitSetup/setup-git-aliases

@@ -36,19 +36,6 @@ git config branch.master.rebase true
 git config rebase.stat true
 git config branch.master.rebase true
 
-# Disable old Gerrit hooks
-hook=$(git config --get hooks.GerritId) &&
-if "$hook"; then
-	echo '
-ITK has migrated from Gerrit to GitHub for code reviews.
-
-Disabling the GerritId hook that adds a "Change-Id" footer to commit
-messages for interaction with Gerrit. Also, removing the "gerrit" remote.' &&
-	git config hooks.GerritId false
-	git config --get remote.gerrit.url > /dev/null && \
-          git remote remove gerrit
-fi
-
 # Record the version of this setup so Hooks/pre-commit can check it.
 SetupForDevelopment_VERSION=1
 git config hooks.SetupForDevelopment ${SetupForDevelopment_VERSION}