[5.5] Fix --force on GeneratorCommand (#23427)

Already merged on 5.6 laravel/framework#23230
Adding the bug fix on 5.5 LTS

GeneratorCommand.php

@@ -56,7 +56,7 @@ public function handle()
         // First we will check to see if the class already exists. If it does, we don't want
         // to create the class and overwrite the user's code. So, we will bail out so the
         // code is untouched. Otherwise, we will continue generating this class' files.
-        if ($this->alreadyExists($this->getNameInput())) {
+        if ((! $this->hasOption('force') || ! $this->option('force')) && $this->alreadyExists($this->getNameInput())) {
             $this->error($this->type.' already exists!');
 
             return false;