Logic error in talawa_plugin_provider.dart file for the visibility of a plugin.

[Dante291]

Describe the bug
There is a logic error in this file.

In this code, condition plugin["installedOrgs"].contains(userConfig.currentOrg.id) as bool` is never getting checked.

This could be fixed with this logic:

This will check both conditions i.e. whether Plugin is installed or plugin is already installed in the specific organization and determine the visibility of the Plugin.

[Dante291]

@noman2002 Its a quick fix, lemme do it.