[openwrt/openwrt] env: only use color diffs on terminals

[LEDE Commits]

blogic pushed a commit to openwrt/openwrt.git, branch master:
https://git.lede-project.org/e495a050693952956a81847669b8b7888b4cd769

commit e495a050693952956a81847669b8b7888b4cd769
Author: Philip Prindeville <philipp at redfish-solutions.com>
AuthorDate: Tue Apr 10 16:57:06 2018 -0600

    env: only use color diffs on terminals
    
    When sending script/env diff's output to a file or pipeline, you
    don't want escape characters for ANSI color sequences fouling the
    byte stream.
    
    Signed-off-by: Philip Prindeville <philipp at redfish-solutions.com>
---
 scripts/env | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/env b/scripts/env
index 63e26eb..84166ae 100755
--- a/scripts/env
+++ b/scripts/env
@@ -104,7 +104,7 @@ env_list() {
 env_diff() {
 	env_init
 	env_sync_data
-	git diff --cached --color
+	git diff --cached --color=auto
 	env_link_config
 }