remove bad truthiness checks

truthy checks were used here, but you'll get
an empty hash which will be treated as true causing
the test to be invalid and allowing for errors further in the method

MSP-9972

Author: David Maloney

lib/rex/parser/appscan_nokogiri.rb

@@ -141,9 +141,9 @@ def parse_params(request_body)
 
     def report_web_page(&block)
       return unless(in_issue && has_text)
-      return unless @state[:web_site]
-      return unless @state[:response_headers]
-      return unless @state[:uri]
+      return unless @state[:web_site].present?
+      return unless @state[:response_headers].present?
+      return unless @state[:uri].present?
       web_page_info = {}
       web_page_info[:web_site] = @state[:web_site]
       web_page_info[:path] = @state[:uri].path