FIX: Rename deprecated "refresh" icon to "sync" (#7966)

FIX: Rename deprecated “refresh” icon to “sync” (#7966)

diff --git a/app/assets/javascripts/discourse/controllers/exception.js.es6 b/app/assets/javascripts/discourse/controllers/exception.js.es6
index 1f4c454..6b341b1 100644
--- a/app/assets/javascripts/discourse/controllers/exception.js.es6
+++ b/app/assets/javascripts/discourse/controllers/exception.js.es6
@@ -17,7 +17,7 @@ const ButtonBackBright = {
     classes: "btn-primary",
     action: "tryLoading",
     key: "errors.buttons.again",
-    icon: "refresh"
+    icon: "sync"
   },
   ButtonLoadPage = {
     classes: "btn-primary",

GitHub sha: 1bb52664