Fix missing function in setup-user script

Add missing getDefaultGitHomebrewURL.

bin/azw-setup-user

@@ -138,6 +138,10 @@ function getHomebrewDirectoryPath() {
 	print -- ${homebrew_prefix:-$(getDefaultHomebrewPrefix)}/Homebrew
 }
 
+function getDefaultGitHomebrewURL() {
+	print -- ${HOMEBREW_BREW_GIT_REMOTE:-https://github.com/Homebrew/brew.git}
+}
+
 function configureFolders() {
 	local dirPath
 	for dirPath in ${HOME}/bin ${HOME}/.vim/{backups,swaps}; do