Use older command for getting current branch name

deploy.sh

@@ -21,7 +21,9 @@ else
 	branch=master
 fi
 
-currentbranch="$(git branch --show-current)"
+# TODO: When deployment is new enough, use the top command.
+#currentbranch="$(git branch --show-current)"
+currentbranch="$(git branch --format '%(refname:short)')"
 
 # If we are not on target branch, switch and run again
 if test "$currentbranch" -ne "$branch"