(re)fix spip mixin

Author: Chocapikk

lib/msf/core/exploit/remote/http/spip.rb

@@ -52,18 +52,15 @@ def spip_plugin_version(plugin_name)
 
       composed_by = res.headers['Composed-By']
       # Case 1: Check if 'Composed-By' header is present and not empty
-      return parse_plugin_version(composed_by, plugin_name) if composed_by&.present?
+      version = composed_by&.present? ? parse_plugin_version(composed_by, plugin_name) : nil
+      return version if version
 
-      composed_by =~ %r{(https?://[^\s]+/local/config\.txt)}i
-      config_url = ::Regexp.last_match(1)
-      config_url ||= normalize_uri(target_uri.path, 'local', 'config.txt')
-
-      # Case 2: Send a request to fetch the config.txt file
+      # Case 2: Extract URL from 'Composed-By' header and send a request to fetch the config.txt file
+      config_url = composed_by =~ %r{(https?://[^\s]+/local/config\.txt)}i ? ::Regexp.last_match(1) : normalize_uri(target_uri.path, 'local', 'config.txt')
       config_res = send_request_cgi('method' => 'GET', 'uri' => config_url)
-      return unless config_res&.code == 200
+      return parse_plugin_version(config_res.body, plugin_name) if config_res&.code == 200
 
-      # Case 3: Parse the content of config.txt to find the plugin version
-      parse_plugin_version(config_res.body, plugin_name)
+      nil
     end
 
     # Parse the plugin version from config.txt or composed-by