fix: typo in success message (#283)

My OCD just kicks in :)) This has bothered me for a long time. Will also update README in https://github.com/appleboy/ssh-action to reflect this change.

Author: 1ukastesar

plugin.go

@@ -230,9 +230,9 @@ func (p Plugin) Exec() error {
 		}
 	}
 
-	fmt.Println("==============================================")
-	fmt.Println("✅ Successfully executed commands to all host.")
-	fmt.Println("==============================================")
+	fmt.Println("===============================================")
+	fmt.Println("✅ Successfully executed commands to all hosts.")
+	fmt.Println("===============================================")
 
 	return nil
 }