fix(git): fetch commit from origin or local to check if branch was changed. See #1549

Author: folke

lua/lazy/manage/task/git.lua

@@ -127,7 +127,7 @@ M.branch = {
       return true
     end
     local branch = assert(Git.get_branch(plugin))
-    return Git.get_commit(plugin.dir, branch)
+    return Git.get_commit(plugin.dir, branch, true)
   end,
   run = function(self)
     local args = {