Fixes panic when there's no user initialized (#358)

cmd/serve.go

@@ -255,11 +255,11 @@ func runServ(c *cli.Context) error {
 					"User %s does not have level %v access to repository %s",
 					user.Name, requestedMode, repoPath)
 			}
+
+			os.Setenv("GITEA_PUSHER_NAME", user.Name)
 		}
 	}
 
-	os.Setenv("GITEA_PUSHER_NAME", user.Name)
-
 	uuid := gouuid.NewV4().String()
 	os.Setenv("GITEA_UUID", uuid)
 	// Keep the old env variable name for backward compability