web--browse: Add a few quotes in 'init_browser_path'.

These changes were made to the 'init_browser_path' function in
'git-instaweb.sh', but was not in 'git-web--browse.sh'.

[jc: the quoting was screwy and did not quote $1 correctly, so
 I fixed it up.]

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

git-web--browse.sh

@@ -34,8 +34,8 @@ valid_tool() {
 }
 
 init_browser_path() {
-	browser_path=`git config browser.$1.path`
-	test -z "$browser_path" && browser_path=$1
+	browser_path=$(git "config browser.$1.path")
+	test -z "$browser_path" && browser_path="$1"
 }
 
 while test $# != 0