Fixes 500 error occurred during refreshing of provider instance

The error occurs only in cases when refresh is done 'after' a reconfigure operation on the provider instance. It was rendering the _resize partial due to a pre-existing value in the @sb[:action]

Fixes rspec failures

Author: elsamaryv

app/controllers/application_controller/explorer.rb

@@ -84,6 +84,8 @@ def x_button
 
     # Process model actions that are currently implemented
     if X_BUTTON_ALLOWED_ACTIONS[action] == :s1
+      # resetting action that was stored during other operations
+      @sb[:action] = nil if @sb
       send(method)
     elsif X_BUTTON_ALLOWED_ACTIONS[action] == :s2
       # don't need to set params[:id] and do find_checked_items for methods