completion: use tabs for indentation

CodingGuidlines confidently declares "We use tabs for indentation."
It would be a shame if it were caught lying.

Signed-off-by: Philip Jägenstedt <philip@foolip.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

contrib/completion/git-completion.bash

@@ -286,13 +286,13 @@ __git_ps1 ()
 				fi
 			fi
 			if [ -n "${GIT_PS1_SHOWSTASHSTATE-}" ]; then
-			        git rev-parse --verify refs/stash >/dev/null 2>&1 && s="$"
+				git rev-parse --verify refs/stash >/dev/null 2>&1 && s="$"
 			fi
 
 			if [ -n "${GIT_PS1_SHOWUNTRACKEDFILES-}" ]; then
-			   if [ -n "$(git ls-files --others --exclude-standard)" ]; then
-			      u="%"
-			   fi
+				if [ -n "$(git ls-files --others --exclude-standard)" ]; then
+					u="%"
+				fi
 			fi
 
 			if [ -n "${GIT_PS1_SHOWUPSTREAM-}" ]; then