Add config path as an optional flag when changing pass via CLI (#4184)

cmd/admin.go

 				Value: "",
 				Usage: "New password to set for user",
 			},
+			cli.StringFlag{
+				Name:  "config, c",
+				Value: "custom/conf/app.ini",
+				Usage: "Custom configuration file path",
+			},
 		},
 	}
 
 		return err
 	}
 
+	if c.IsSet("config") {
+		setting.CustomConf = c.String("config")
+	}
+
 	if err := initDB(); err != nil {
 		return err
 	}

docs/content/doc/usage/command-line.md

         - Options:
             - `--username value`, `-u value`: Username. Required.
             - `--password value`, `-p value`: New password. Required.
+            - `--config path`: Gitea configuration file path. Optional. (default: custom/conf/app.ini).
         - Examples:
             - `gitea admin change-password --username myname --password asecurepassword`
     - `regenerate`