[5.4] Add ability to remove a global scope with another global scope (laravel#19657)

* Fix laravel#19282

* Fix import order

* Update Builder.php

Author: KKSzymanowski

src/Illuminate/Database/Eloquent/Builder.php

@@ -889,7 +889,11 @@ public function applyScopes()
 
         $builder = clone $this;
 
-        foreach ($this->scopes as $scope) {
+        foreach ($this->scopes as $identifier => $scope) {
+            if (! isset($builder->scopes[$identifier])) {
+                continue;
+            }
+
             $builder->callScope(function (Builder $builder) use ($scope) {
                 // If the scope is a Closure we will just go ahead and call the scope with the
                 // builder instance. The "callScope" method will properly group the clauses