Fixed errcheck issues in server/channels/api4/license_local.go (#28558)

Co-authored-by: Ben Schumacher <ben.schumacher@mattermost.com>

server/.golangci.yml

@@ -74,7 +74,6 @@ issues:
         channels/api4/data_retention.go|\
         channels/api4/file_test.go|\
         channels/api4/job_test.go|\
-        channels/api4/license_local.go|\
         channels/api4/post_test.go|\
         channels/api4/preference_test.go|\
         channels/api4/reaction_test.go|\

server/channels/api4/license_local.go

@@ -54,7 +54,10 @@ func localAddLicense(c *Context, w http.ResponseWriter, r *http.Request) {
 	defer file.Close()
 
 	buf := bytes.NewBuffer(nil)
-	io.Copy(buf, file)
+	if _, err := io.Copy(buf, file); err != nil {
+		c.Err = model.NewAppError("addLicense", "api.license.add_license.copy.app_error", nil, "", http.StatusInternalServerError).Wrap(err)
+		return
+	}
 
 	license, appErr := c.App.Srv().SaveLicense(buf.Bytes())
 	if appErr != nil {

server/i18n/en.json

@@ -2234,7 +2234,7 @@
   },
   {
     "id": "api.license.add_license.copy.app_error",
-    "translation": "Failed to copy license."
+    "translation": "Failed to copy license file content to buffer"
   },
   {
     "id": "api.license.add_license.expired.app_error",